00n=z oticab ll-rsesaom, nf-lsvd praove eqmsbm corn model.a umeed w sinummdie s~oprna of...

NPS- OC-94-006

NAVAL )gRRADUCE SCHOOLL Monterey, California

00N=z

OTICELECTF

THESIS

A NUMERICAL STUDY OFWIND FORCING EFFECTS ON THECALIFORNIA CURRENT SYSTEM

by

James R. Vann

September, 1994

Thesis Advisor: Mary L. Batteen

Approved for public release; distribution is unlimited.

Prepared for:Office of Naval Research800 N. Quincy StreetArlington, VA 22217-5000

r 7D

94-35200Ill!l|~fli,

NAVAL POSTGRADUATE SCHOOLMonterey, CA 93943

Rear Admiral Thomas A. MercerSuperintendent

Thi e• was prepared in conjunction with research sponmored in pan bythe Office of Naval Research, 800 N. Quincy Street, Arlington, VA 22217-5000.

Reproduction of all or pat of this qpox is authorized.

Relead by:

I a fResearch

faro~ m~1 ab s.febsn at' .1m~ is samed to Is I bw Pa apoefti, ~beief on disw sevissria I e-"6 1.- Ie mm 8 sai minesan on am smeic Mcmpisf M in assuw saffessi of'~ I .edsammi . 11 busdesafe~ of My ase ampassa dai eafestmb ah 1un inh 1001af 0481Wfa wine ft bumdes. 1 WeWi "HI Sevis , Dwassmu. farWm. I pu -i 0 l- napeft. 1215 i0omism Davi Ifh-ws, as's 120, Abeam. VA 2230-32~.4Lmalis Oi~ f isshmavnt mi swep.

PIP" a (OS) mDC2o

I1. AGENCY USE ONLY o4encb~mk) j2. REPORT DATE ~ 3. REPORT TYPE AND DATES COVERED41 1 WkMasier's Thesis

4. TITLE AND SUBTITLE A NUMIERICAL STUDY OF WIND FORCING S. FUNDING NUMBERSEFFECTS' ON THE CALIFORNIA CURRENT SYM~M (U)

6. AUTHOR(S) Vann, James R. a oo%*mom vi mar Besmn

7. PERFORMING ORGANIZATION NAME(S) AND ADDREZS(ES) 8.PERFORMINGNaval Pos4a'paua School ORGANIZATIONNmoodey CA 93943-S00 REPORT NUMBER

NPS-OC-4W-006

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESI(ES) 10. IPONSORING/MONITORINGOffice of N"~v Resarcli AGENCY REPORT NUMBER300 N.- Qummy St.

Abgo.VA 22217-500

11- SUPPLEMENTARY N01S noe view expessed in this thesis ame ibm of the author azxd do not reflectthe officia policy or pmosido of the Departmnet of Defense or the U.S. Government,

12A. DISTRI3UTION/AVAILADUJLTY STATEMENT 12b. DISTRIBUTION CODEApproved for public releas; disvibution is unlimitied. j A

13. ABSTRACT Asiiaa20 used)

Ab ll-rsesaom, nf-lsvd praove eqmsbm corn model.a umeed w sinummdie s~oprnA of sanideelized, fle-booom.asee bosmndery oosamic regimse as a beft-hns lo climological averae (1950-939), individual yew, a~d .okqkl yew windkiting. 71e focus of 6o Nody Jsdie Ca~ofmsa Curmen Syism alongs di. amend regica, home 3S* N so 4730* N, off &c. Weetrom of Noedi America.

Two types of e;ipmn - w conduichud. Min first type fores die mode[ from 'rest wil dlimebological, 1981, and 1983Mondaly aid 10 examie dk. 2ero - pseof beesur. nuch sis awrrm, upwefling, meansders, eddie., and filaments. Tie

esodtype oomemus die forcing from die previous ye.ts loeainns di nasiatmace of dines. features.In die Em type of ea1. di f-Owl*lowing fesures ame observed: a polowad coastal sorface current nar die start and

end of sabb yewr, -m eyuirawwud nufacs anrea, a polaward undercuirrent, upwalling, meanders, and eddies. In die meooed typeof experemeews meanders and eddies were already presentat di. start of de exerimeeta. in addition to die features observedduring Owe fire type of eparsen, filamemsaama generated. The results support die hypodiess dia wind forcing is an inuortantmescumai fo die gemerstiom of may of die observed fetue in die CAlifonsia Current Systemi.

14. SUBJECT TERMS Primitive equation Model, California Current System, eddies, 15. NUMBER OFfilament, jets, undercurrent, wind forcing, curns PAGES 235

16. PRICE CODE17. SECURITY CLASSIFI- Is. SECURITY CLASSIFI- 19. SECURITY CLASSIFI- 20. LIMITATION OF

CATION OF REPORT CATION OF THIS PAGE CATION OF ABSTRACT ABSTRACTUnlUnclassi fncasfed Unclassified UL

NSN 7540401-230-550 Standard Form 298 (Rev. 2-89)Puawijie by ANSI Std. 239-18

Approved for public release; distribution is unlimited.

A NUMERICAL STUDY OFWIND FORCING EFFECTS ON THE

CALIFORNIA CURRENT SYSTEM

by

James R. VannLieutenant, United States Navy

B.S., United States Naval Academy, 1984

Submitted in partial fulfillment

of the requirements for the degree of

MASTER OF SCIENCE IN

METEOROLOGY AND PHYSICAL OCEANOGRAPHY

from the

NAVAL POSTGRADUATE SCHOOLSeptember 1994

Author:__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

James R. Vann

Approved by: A .

Mary L. Batteen, Thesis Advisor

ellL

Curtis A. Collins, Second Reader

Robert H. Bourke, Chairman,

Department of Oceanography

ABSTRACT

A high-resolution, multi-level, primitive equation ocean model is used to

examine the response of an idealized, flat-bottom, eastern boundary oceanic

regime on a beta-plane to climatological average (1980-1989), individual year,

and multiple year wind forcing. The focus of this study is the California Current

System along the coastal region, from 350 N to 47.5* N, off the West Coast of

North America.

Two types of experiments are conducted. The first type forces the model

from rest with climatological, 1981, and 1983 monthly winds to examine the

generation phase of features such as currents, upwelling, meanders, eddies, and

filaments. The second type continues the forcing from the previous years to

examine the maintenance of these features.

In the first type of experiments, the following features are observed: a

poleward coastal surface current near the start and end of each year, an

equatorward surface current, a poleward undercurrent, upwelling, meanders, and

eddies. In the second type of experiments, meanders and eddies were already

present at the start of the experiment. In addition to the features observed during

the first type of experiment, filaments are generated. The results support the

hypothesis that wind forcing is an important mechanism for the generation of

many of the observed features in the California Current System.Aw.~ !.L t

v -'Aval a-x/orD~st Spd.aia

TABLE OF CONTENTS

I. INTRODUCTION ................... 1

II. BACKGROUND ..... 3A. BRIEF DESCRIPTION OF REGION . . .. . ".. . . . 3B. CLIMATOLOGICAL WINDS..............................5C. EL NISO-SOUTHERN OSCILLATION. ........ . 7D. NUMERICAL MODEL STUDIES .................. .... 8

III. MODEL DESCRIPTION AND EXPERIMENTAL DESIGN . . . 19A. MODEL DESCRIPTION ......... ................ 19

1. Basic Model .......... ............... 192. Friction ... ......... ............... 193. Boundary Conditions .... . . . ............ 204. Domain and Resolution . . ................. 205. Finite Difference Scheme ................. 216. Method of Solution .... ............ .. 227. Initial Conditions ..... ............ .. 22

B. WIND AND ATMOSPHERIC FORCING ... ......... .. 22C. SPECIFIC EXPERIMENTAL DESIGN ... ......... .. 23D. ENERGY ANALYSIS TECHNIQUES ... .......... .. 24

IV. RESULTS OF EXPERIMENTS ._......... . .... 25A. EXPERIMENTS STARTED FROM REST .. ................. 25

1. Experiment 1 - Climatological Winds. . 252. Experiment 2 - 1981 Winds ...... ...... 293. Experiment 3-l1983Winds .. ................. 314. Summary of First Year Run Results ... .. 33

B. EXPERIMENTS SPUN UP FROM THE PREV.TOUS YEAR . 341. Experiment 4 - Climatological Winds . . .. 342. Experiment 5 - 1982 Winds ... ......... .. 363. Experiment 6 - 1984 Winds...... . . ... 384. Summary of Second Year Run Results . . . 405. Experiment 7 - Multiple Climatological Runs 416. Experiment 8 - Multiple Years (1981 - 1984) 427. Summary of Multiple Year Run Results . . . 44

V. SUMMARY AND RECO4MMENDATIONS ...... ............ .. 133A. SUMMARY................ ............ ..... 133B. COMPARISON WITH OBSERVATIONS DURING AN EL NI O

YEAR .............. ..................... 136C. NAVAL RELEVANCE .......... ................ 137D. RECOMMENDATIONS .......... ................ 138

vii

APPENDIX A. INSTABILITIES FOR EXPERIMENT 1 (CLIMO) . . 149

APPENDIX B. INSTABILITIES FOR EXPERIMENT 2 (1981) . . 157

APPENDIX C. INSTABILITIES FOR EXPERIMENT 3 (1983) . 167

APPENDIX D. INSTABILITIES FOR EXPERIMENT 4 (CLIMO II) 183

APPENDIX E. INSTABILITIES FOR EXPERIMENT 5 (1982) . . 193

APPENDIX F. INSTABILITIES FOR EXPERIMENT 6 (1984) . . 199

LIST OF REFERENCES ............. .................. 207

INITIAL DISTRIBUTION LIST .......... .............. 211

viii

LIST OF TABLES

4.1 SUMMARY OF INSTABILITIES FOR CLIMATOLOGICALYEAR (TOP), 1981 (CENTER), AND 1983 (BOTTOM). 46

4.2 SUMMARY OF EXPERIMENTS - FIRST YEAR ......... .. 474.3 SUMMARY OF INSTABILITIES FOR CLIMATOLOGICAL II

YEAR (TOP), 1982 (CENTER), AND 1984 (BOTTOM). 484.4 SUMMARY OF EXPERIMENTS - SECOND YEAR ........ .. 494.5 SUMMARY OF EXPERIMENTS - MULTIPLE YEARS ........ 505.1 COMPARISON OF OBSERVED AND MODEL RESULTS DURING

AN EL NINO YEAR (1983) ..... ............. 140

ix

LIST OF FIGUR=S

2.1 Generalized circulation schematic of theCalifornia Current System (CCS). .... . ... ... 11

2.2 Section of California Current System withschematized positions of jets and synoptic-scale eddies .......... ................ ... 12

2.3 Domain of model off the western coast of theUnited States of America ............ ....... . 13

2.4 Map of a portion of the west coast of NorthAmerica, showing the location of some of thepast studies in the CCS ........... ...... . . 14

2.5 Long-term mean atmospheric pressure at sealevel for (a) January and (b) July .... ...... 15

2.6 Long-term (1854-1972) mean wind stress(dynes cm"2 ) by one-degree squares, fromship reports .................... ....... ... 16

2.7 An illustration of the distributions of keyproperties involved in the teleconnectionprocess during a typical E1 Niflo-SouthernOscillation event ................ ..... ... 17

4.1 Mid-monthly averaged climatological (1980 -1989) ECMWF winds in m s-1: (a) January,(b) February, (c) March, (d) April, (e) May,(f) June, (g) July, (h) August, (i)September, (j) October, (k) November, and(1) December ........ .................. ... 51

4.1 (continued) ........ .................. ... 524.1 (continued). ....... . 534.2 Experiment 1: Surface meridio'nalcomponent

of velocity at day 30.. . . .. . ... 544.3 Experiment 1: Surface velocity'vectors at

day 90 ............. ... ......... 554.4 Experiment 1: Cross-section at y~704 *km

(41.250 N) of the meridional component ofvelocity at day 60 ........ ............ ... 56

4.5 Experiment 1: Cross-section at y-704 km(41.250 N) of the meridional component ofvelocity at day 90 ........ .............. ... 57

4.6 Experiment 1: Surface temperature at day120 ........................ ...... .... 58

4.7 Experiment 1: Surface velocity vectors atday 210. ......................... ......... 59

4.8 Experiment 1: Surface temprature at day210 .......................... ........... 60

4.9 Experiment 1: Surface temperature at day240 ........... ........................ 61

xi

4.10 Experiment 1: Surface velocity vectors atday 240 .......... ................... .. 62

4.11 Experiment 1: Surface temperature at day360 ........................... 63

4.12 Experiment 1: Surface velocity vectors atday 360 ........... .................... .. 64

4.13 Experiment 1: Cross-section of themeridional component of velocity at day360. . ................. ........ . ...... .. 65

4.14 Experiment 1: Total kinetic energy per unitmass time series for climatological (1980-1989) year over the entire domain . . .... . .. 66

4.15 Mid-monthly ECMWF winds for 1981 in m(a) January, (b) February, (c) March, (d)April, (e) May, (f) June, (g) July, (h)August, (i) September, (j) October, (k)November, and (1) December ............. .... 67

4.15 (continued) ........ .................. .. 684.15 (continued) ......... .................. .. 694.16 Experiment 2: Surface meridional component

of velocity at day 45 ........... ...... . . 704.17 Experiment 2: Surface velocity vectors at

day 90 ................. 714.18 Experiment 2: Cross-section at'y-704 km

(41.250 N) of the meridional component ofvelocity at day 90 .......... .......... ... 72

4.19 Experiment 2: Layer 5 (316 m) velocityvectors at day 210 ...... ............... ... 73

4.20 Experiment 2: Surface temperature at day120............ . ... 74

4.21 Experiment 2: Surface velocity vectors atday 210. ......... .... 75

4.22 Experiment 2: Surface temperatu~re at day210. . ..... .Surface -- . . .vectos .a . 76

4.23 Experiment 2: Surface velocity vectors atday 270. . ................................... 77

4.24 Experiment 2: Surface temperature at day270........................... . . ..... 78

4.25 Experiment 2: Surface temperature at day360 ........................ ........ ..... 79

4.26 Experiment 2: Cross-section at y-704 km(41.250 N) of the meridional component ofvelocity at day 360.. . . . _........ . ... 80

4.27 Experiment 2: Total kinetic energy per unitmass time series for 1981 over the entiredomain ............................ ... .... . 81

4.28 Mid-monthly ECMWF winds for 1983 in m(a) January, (b) February, (c) March, (d)April, (e) May, (f) June, (g) July, (h)August, (i) September, (j) October, (k)November, and (1) December .............. .... 82

xii

4.28 (continued) . . . . . . . . . . . . . . . . . . 834.28 (continued) .. .. . .. . .. . 844.29 Experiment 3: Surface velocity vectors at

day 30 ...... ... .............. ..... 854.30 Experiment 3: Surface velocity vectors at

day 120. ................. ................. 864.31 Experiment 3: Cross-section at y-704 km,

(41.250 N) of the meridional component ofvelocity at day 90 ..... ............... .... 87

4.32 Experiment 3: Surface temperature at day150........ ........... . . 88

4.33 Experiment 3: Surface velocity'vectors atday 150. ..... . .... 89

4.34 Experiment 3: Surface velocity'vector, atday 240. ..................... 90

4.35 Experiment 3: Surface temperature at day240 ...... . ........... ... 91

4.36 Experiment 3: Surface temperature at day360 .......... *............ . 92

4.37 Experiment 3: Cross-;ection it'y:704 km(41.250 N) of the meridional component ofvelocity at day 360. . .... 93

4.38a Experiment 3: Total kinetic energ.yper'unitmass time series for 1983 (days 1-306) overthe entire domain. ............ . ... 94

4.38b Experiment 3: Total kinetic energy per unitmass time series for 1983 (days 309-363)over the entire domain ..... ....... ... ... 95

4.39 Experiment 4: Surface velocity vectors atday 396 (yd 30) .......... ......... .. .... 96

4.40 Experiment 4: Surface temperature at day 396(yd 30). ... ....... 97

4.41 Experiment 4: Cross-section at'y:704 **m(41.250 N) of the meridional component ofvelocity at day 426 (yd 60) ..... ..... .. ... 98

4.42 Experiment 4: Surface temperature at day 546(yd 180) ..... ......... . 99

4.43 Experiment 4: Surface temperature at da'y606(yd 240) ....................... ..... ... 100

4.44 Experiment 4: Surface velocity vectors atday 456 (yd 9o) . ... ....._ 101

4.45 Experiment 4: Cross-section at Y'-704km(41.250 N) of the meridional component ofvelocity at day 666 (yd 300)... . .. .......... 102

4.46 Experiment 4: Surface temperature at day 696(yd 330) .... .. ............. 1034.47 Experiment 4: Surface temperature at day 726(yd 360)........................... . . ... 104

4.48 Experiment 4: Total kinetic energy per unitmass time series for Climo II over theentire domain ............ ................. 105

xiii

4.49 Kid-monthly IOU? winds for 1962 in a 3"1:

(a) January, (b) February, (c) March, (d)April, (e) May, (f) June, (9) July, (h)August, (i) September, (j) October, Wk)November, and (1) December .... ........... ... 106

4.49 (continued) .......... .................. .. 1074.49 (continued). .I.............................. 1084.50 Experiment 5: Surface velocity vectors at

day 396 (yd 30) ...... ................ ... 1094.51 Experiment 5: Surface meridional component

of velocity at day 426 (yd 60) ...... ........ 1104.52 Experiment 5: Cross-section at y-704 km

(41.25' N) of the meridional component ofvelocity at day 426 (yd 60) ...... ..... .111

4.53 Experiment 5: Surface velocity vectors atday 426 (yd 60) ........ ............... ... 112

4.54 Experiment 5: Surface temperature at day 516(yd 150) ........................ ....... 13

4.55 Experiment 5: Surface temperature at day 6;6(yd 240) ................................ * * _ 114

4.56 Experiment 5: Surface temperature at day 696(yd 330) .......... 115

4.57 Experiment 5: Totai kinetic ene'rgy perunitmass time series for 1982 over the entiredomain ............................. .... .. 116

4.58 Mid-monthly 306fF winds for 1984 in m s'1:(a) January, (b) February, (c) March, (d)April, (e) May, (f) June, (g) July, (h)August, (i) September, (j) October, (k)November, and (1) December ............... ... 117

4.58 (continued) .......... .................. ... 1184.58 (continued) .............. ............. ... 1194.59 Experiment 6: Surface velocity vectors at

day 396(yd 30) .............. ....... ... 1204.60 Experiment 6: Surface meridional component

of velocity at day 426 (yd 60) .......... 1214.61 Experiment 6: Cross-section at y-704 kJ

(41.250 N) of the meridional component ofvelocity at day 546 (yd 180) .... .......... .. 122

4.62 Experiment 6: Surface temperature at day 456(yd 90). . . . 123

4.63 Experiment 6: Surface- t _em-perature at'da•y576" ,(yd 210). . . . ............. ... 124

4.64 Experiment 6: temperature at day 666(yd 300).. . 125

4.65 Experiment 6: Totai kinetic energy per unitmass time series for 1984 over the entiredomain .......... 126

4.66 Experiment 7: Total kinetic energy*per'unit"mass time series for Climo III over theentire domain ......... ................. ... 127

xiv

4.67 Experiment 7: Total kinetic energy per unitmass time series for Climo IV over theentire domain ......... ................. ... 128

4.68 Experiment 7: Total kinetic energy per unitmass time series for Climo, Climo II, ClimoIII, and Climo IV over the entire domain . . 129

4.69 Experiment 8: Total kinetic energy per unitmass time series for 1983 over the entiredomain ........................... ............ 130

4.70 Experiment 8: Total kinetic energy per unitmass time series for 1984 over the entiredomain ............................ .... .. 131

4.71 Experiment 8: Total kinetic energy per unitmass time series for 1981, 1982, 1983, and1984 over the entire domain .. . . ... . . ...

5.1a Experiments 1-3: Total kinetic energy perunit mass time series for climatology (1980-1989), 1981, and 1983 over the entiredomain . .............. 141

5.1b Experiments 1-3: Mean kinetic energy perunit mass time series for climatology (1980-1989), 1981, and 1983 over the entiredomain ................ 142

5.1c Experiments 1-3: Eddy kinetic energy perunit mass time series for climatology (1980-1989), 1981, and 1983 over the entiredomain ...................... ............ .. 143

5.2a Experiments 4-6: Total kinetic energy perunit mass time series for Climo II, 1981,and 1983 over the entire domain ........... .. 144

5.2b Experiments 4-6: Mean kinetic energy perunit mass time series for Climo II, 1981,and 1983 over the entire domain ........... .. 145

5.2c Experiments 4-6: Eddy kinetic energy perunit mass time series for Climo II, 1981,and 1983 over the entire domain ........... .. 146

5.3 Experiment 3: Surface meridional componentof velocity at day 45 ..... ............. ... 147

A.1 Experiment 1: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for climatological (1980-1989)year, for model days 207 to 216 ........... .. 150

A.2 Experiment 1: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) forclimatological (1980-1989) year, for modeldays 207 to 216 ........ ........... 151

A.3 Experiment 1: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for climatological (1980-1989)year, for model days 228 to 231 ........... .. 152

xv

A.4 Experiment 1: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) forclimatological (1980-1989) year, for modeldays 228 to 231. .. .............. 153

A.5 Experiment 1: Energy transfers'of mean toeddy kinetic energy (i.e., barotropic energytransfer) for climatological (1980-1989)year, for model days 297 to 303 ........... ... 154

A.6 Experiment 1: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) forclimatological (1980-1989) year, for modeldays 297 to 303. .................. ... 155

B.1 Experiment 2: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for 1981, for model days 210 to222 ......... .... ..... 158

B.2 Experiment 2: Energytransfers of eddy

potential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1981, formodel days 210 to 222... ............. ...... 159

B.3 Experiment 2: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for 1981, for model days 240 to252 ............................... ....... 160

B.4 Experiment 2: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1981, formodel days 240 to 252 ........ ........ ... 161

B.5 Experiment 2: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for 1981, for model days 297 to303 ................. 162

B.6 Experiment 2: Energy trnfrso;ddy*potential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1981, formodel days 297 to 303 ............ ..... ... 163

B.7 Experiment 2: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for 1981, for model days 309 to333 ................ ..... 164

B.8 Experiment 2: Energy transfers'of eddy"potential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1981, formodel days 309 to 333 ........ .......... ... 165

C.1 Experiment 3: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for 1983, for model days 186 to192 .............. ...................... ... 168

xvi

C.2 Experiment 3: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1983, formodel days 186 to 192 .... ............. 169

C.3 Experiment 3: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for 1983, for model days 222 to234. . ........... ..... 170

C.4 Experiýent 3: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1983, formodel days 222 to 234. .............. 171

C.5 Experiment 3: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for 1983, for model days 249 to258. .......... 172

C.6 Experint 3: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1983, formodel days 249 to 258 .... ............. 173

C.7 Experiment 3: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for 1983, for model days 279 to288 ........................ 174

C.8 Experiment 3: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1983, formodel days 279 to 288 ................ 175

C.9 Experiment 3 Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for 1983, for model days 312 to315 .................... ......... . . 176

C.10 Experiment 3: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1983, formodel days 312 to 315 .... ............. 177

C.11 Experiment 3: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for 1983, for model days 324 to327 ........................... ........... 178

C.12 Experiment 3: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1983, formodel days 324 to 327. . ............ 179

C.13 Experiment 3: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for 1983, for model days 342 to348 .............. ...................... ... 180

xvii

C.14 Experiment 3: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1983, formodel days 342 to 348 ..... ............. ... 181

D.1 Experiment 4: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for Climo II, for model days 378to 408 (yd 12 - 42). ......................... 184

D.2 Experiment 4: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for Climo II,for model days 378 to 408 (yd 12 - 42) ........ 185

D.3 Experiment 4: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for Climo II, for model days 453to 465 (yd 87 - 99). ....... ..... 186

D.4 Experiment 4: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for Climo II,for model days 453 to 465 (yd 87 - 99) ........ 187

D.5 Experiment 4: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for Climo II, for model days 504to 516 (yd 138 - 150) .......... ........... 188

D.6 Experiment 4: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for Climo II,for model days 504 to 516 (yd 138 - 150) . ... 189

D.7 Experiment 4: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for Climo II, for model days 624to 636 (yd 258 - 270). .............. 190

D.8 Experiment 4: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for Climo II,for model days 624 to 636 (yd 258 - 270) . ... 191

E.1 Experiment 5: Energy transfers of mean toeddy kinetic energy (i.e-, barotropic energytransfer) for 1982, for model days 507 to516 (yd 141 - 150). . ............. 194E.2 Experiment 5: Energy'transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1982, formodel days 507 to 516 (yd 141 - 150) ........ .. 195

E.3 Experiment 5: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for 1982, for model days 525 to528 (yd 159 - 162) ........................... 196

xviii

3.4 Experiment 5: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1982, formodel days 525 to 528 (yd 159 - 162). ...... 197

F.1 Experiment 6: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for 1984, for model days 576 to591 (yd 210 - 225) ........ . .......... 200

F.2 Experiment 6: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1984, formodel days 576 to 591 (yd 210 - 225) ........ .. 201

F.3 Experiment 6: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for 1984, for model days 606 to624 (yd 240 - 258) .................. 202F.4 Experiment 6: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1984, formodel days 606 to 624 (yd 240 - 258). ..... 203

P.5 Experiment 6: Energy transfers of mean toeddy kinetic energy (i.e., barotropic energytransfer) for 1984, for model days 645 to657 (yd 279 - 291) ............ ..... 204P.6 Experiment 6: Energy transfers of eddypotential to eddy kinetic energy (i.e.,baroclinic energy transfer) for 1984, formodel days 645 to 657 (yd 279 - 291) ........ .. 205

xix

A C-------- -T

The author wants to thank Dr. Mary Batteen for her

guidance and patience during the work in performing this

investigation. Additional thanks to Mike Cook for his

endless assistance with UNIX, FORTRAN, and MATLAB

progranmTing, and to Pete Braccio for his invaluable

assistance with numerous model runs and visualization of the

results.

xxi

I. INTRODUCTION

The California Current System (CCS) is an eastern

boundary current (EBC) off the west coast of the United

States of America. A primitive equation numerical model

developed by Batteen et al. (1989) is used to simulate the

currents, eddies and filaments in the CCS. In this study

monthly winds from the European Centre for Medium-Range

Weather Forecasts (ECMWF) global data set from 1980 to 1989

(which include El Niflo events) are used to force the model.

The thesis is organized as follows: Chapter II

describes the region modeled, the El Nifto-Southern

Oscillation (ENSO), and some previous modeling work in this

region. The numerical model which was used here along with

the experimental setup are presented in Chapter III. The

results of the various model simulations are presented in

Chapter IV. Chapter V sunmarizes the work, discusses naval

relevance, and presents recommendations for future research.

Comparisons of model simulations with available observations

are shown in both Chapters IV and V. Six appendices follow

which contain the detailed results of the barotropic and

baroclinic instability analyses for the main experiments.

1

II. BACKGROUND

A. BRIEF DESCRIPTION OF REGION

The west coast of North America serves as an eastern

boundary for the circulation of water in the North Pacific

Ocean. The entire flow along the coast is referred to as

the CCS, which is a classical subtropical EBC system.

The CCS consists of three separate component flows, each

of which varies both spatially and seasonally (see Figure

2.1): an equatorward surface current, a poleward

undercurrent and a poleward surface current adjacent to the

coast (Tisch &t al., 1992). This latter current can be a

surface manifestaLion of the undercurrent or a separate

current.

The predominant flow is an equatorward surface flow

called the California Current (CC). The second basic flow

is the poleward undercurrent which has been called both the

California Undercurrent (CUC) (e.g., by Batteen = al.,

1989) and the California Counter Current (CCC) (e.g., by

Hickey, 1979). Thiq is a relatively weak subsurface flow

(around 5 cm a-1).

The third basic flow is the Inshore Current (IC), which

is known as the Davidson Current (DC) north of Pt.

Conception. This is also a relatively weak poleward flow

3

found at the surface and near the coast. There are other

ICs known as the Southern California Countercurrent (SCC) to

the south, and the Southern California Eddy (SCE) inshore of

the Channel Islands within the California Bight (Hickey,

1979), which are both equatorward of the model region (see

below) to be studied.

The CC is a broad, slow (-10 cm s-1) flow which can

extend offshore around 1000 km (Hickey, 1979). Superimposed

on this mean flow are highly energetic mesoscale eddies and

meandering jets which can have peak velocities near 80 cm

s-1 (Mooers and Robinson, 1984). Figure 2.2 depicts these

features.

A section of the CCS from 350 to 47.50 N and extending

12.5 degrees offshore from the coast will be the model study

area and is depicted in Figure 2.3. Major observational

programs which have sampled this region are quite numerous

and include: California Cooperative Oceanic Fisheries

Investigation (CalCOFI), Coastal Ocean Dynamics Experiment

(CODE) I and II, Large-Scale West Coast Shelf Experiment

(nicknamed SuperCODE), Coastal Upwelling Experiment (CUE) I

and II, Ocean Prediction Through Observation, Modeling and

Analysis program (OPTOMA), and Central California Coastal

Circulation Study (CCCS). Figure 2.4 depicts some of the

areas of observations.

4

B. CLIKATOLOGICAL WINDS

The North Pacific Subtropical High dominates the

atmospheric circulation off the west coast of the United

States of America, and varies in position and strength by

season (Huyer, 1983). In the winter (January) the high is

about 1020 mb and centered near 300 N, 1350 W (Figure 2.5a).

In the summer (July) the pressure increases to 1025 mb and

the center moves northward to 380 N, 1500 W (Figure 2.5b).

Over the continental west coast the typical pressure is 1020

mb in the winter, and 1015 mb during the summer, the latter

in response to a thermal low (of 1005 mb) in the central

valley of California (Huyer, 1983). This results in a

tighter pressure gradient against the west coast during the

summer. As this gradient tightens, stronger winds can

result.

Propagating atmospheric disturbances (Halliwell and

Allen, 1987), along with other atmospheric mesoscale

phenomena (Huyer, 1983), further complicate the wind pattern

on a daily, as well as on a seasonal basis along the coast.

The winds are also affected by coastal atmospheric boundary

layer processes within 100 to 200 km of the coast (Halliwell

and Allen, 1987).

The oceanic response to summer and winter wind patterns

are most notable near the coast. The equatorward winds of

summer can produce nearshore upwelling, while the divergent

5

wind flow of winter can force downwelling in some areas

(Rienecker and Mooers, 1986).

The shifting of the Pacific High, along with the

Aleutian Low moving to the southeast, can cause the winds to

diverge near Cape Mendocino (located at about 400 N) during

the winter. North of the Cape, northerly winds are

encountered as the wind blows around the eastern side of the

Aleutian Low, while south of the Cape, southerly winds

result as wind flows around the North Pacific High.

The summer wind pattern is established by the

interaction between the North Pacific High and the thermal

low in the southwest United States (Nelson, 1977; Halliwell

and Allen, 1987). Winds are predominately equatorward on

both sides of Cape Mendocino during the summer (Nelson,

1977).

Climatological wind stress fields, shown in Figure 2.6

for the months of January, April, July, and October, depict

regions of maximum wind stress in the CCS as shaded areas.

The strongest wind stress is located off Point Conception in

April and migrates northward until it is at a maximum in

July off Cape Mendocino. The average summer wind stress

close to the shore is equatorward and is thus favorable for

upwelling at the coast (Halliwell and Allen, 1987; Nelson,

1977; Wickham ej al., 1987).

6

C. IL NIIO-SOUTEMN OSCILLATIXN

One large-scale two way coupling of the atmosphere and

ocean has been studied for many years and is referred to as

the El Niflo-Southern Oscillation (ENSO). El Niflo refers to

the warming of Eastern Pacific ocean waters, while the

Southern Oscillation is an atmospheric pressure fluctuation

between the Indian Ocean and the Eastern Tropical Pacific

Ocean (Philander, 1990). Figure 2.7 illustrates key

properties of the teleconnection including upper troposphere

and surface pressure anomalies. Note the shift in the

Eastern Pacific Subtropical High during an ENSO event.

Explanations for this phenomena involve both an oceanic

and atmospheric teleconnection. Rienecker and Mooers (1986)

explain that the oceanic connection occurs when eastward

propagating equatorial Kelvin waves turn poleward upon

impacting the west coast of the Americas. In contrast, the

atmospheric teleconnection links the tropical sea surface

temperature (SST) anomalies to the Aleutian Low by momentum

transfer through an intensified Hadley Cell circulation

(Bjerknes, 1966; Philander, 1990). A stronger poleward wind

stress subsequently develops at the coast near 360 N when

the Aleutian Low deepens and moves to the southwest.

Simultaneously the North Pacific High weakens and moves

offshore.

The El Nifto of 1982 - 1983 was one of the strongest on

record. The Aleutian Low was much deeper than normal during

7

the winter and wind stress anomalies were at a maximum in

the region between 350 N and 450 N (Trenberth et al., 1990).

Anomalous conditions were observed from San Diego to

Vancouver Island (Rienecker and Mooers, 1986). There were

two anomalous peaks in the SST, the first occurring in

February to March of 1983 off northern California, while the

second one was evident in September to October of 1983 near

Point Conception (Rienecker and Mooers, 1986), the latter

equatorward of our model domain.

D. NUMERICAL MODEL STUDIES

There have been numerous models used over the past few

decades to model EBCs. particularly the CCS. Extensive

reviews can be found in Allen (1980), Chelton (1984), and

O'Brien = al. (1977). No attempt is made to provide a

comprehensive review of the models here; instead, a summary

of modeling work that has led directly to this study is

presented.

Early work included that of Pedlosky (1974) and

Philander and Yoon (1982) who used steady wind stress and

transient wind forcing, respectively. Carton (1984) and

Carton and Philander (1984) investigated the response of

reduced gravity models to realistic coastal winds. At

periods exceeding 100 days the alongshore currents began to

weaken and disperse as a series of alternating jets.

8

Another series of experiments were done by McCreary eJ

Al. (1987) utilizing a linear model with both transient and

steady wind forcing with Laplacian diffusion in which no

eddies or filaments developed. This work was extended using

a full primitive equation model by Tielking (1988) who

obtained similar results.

Batteen t al. (1989) used a primitive equation, multi-

level model with biharmonic heat and momentum diffusion

which had both steady forcing constant throughout the domain

and meridionally varying forcing. In both cases, when the

baroclinic shear between the surface current and

undercurrent became strong enough, eddies and filaments

developed. This was the first EBC model to simulate

currents, eddies and jets in the CCS.

The work of Batteen r& &1. (1989) was extended by

Mitchell (1993) and Haines (1994). Mitchell (1993) forced

the model with different sets of averaged winds and obtained

reasonable results utilizing a set of seasonally varying

full climatological wind fields. Haines (1994) enlarged the

model domain, improved resolution to 8 x 13 km and used

interannual vice steady or seasonal winds.

This effort builds on the model used by Batteen et al.

(1989) and the work of Mitchell (1993) and Haines (1994).

The computer code for the model has been modified to include

a barotropic component, while the model resolution has been

refined to 8 x 11 km grid spacing. Seasonal and interannual

9

wind forcing was used to force the model. Model simulation

times have been expanded from one year, as in Mitchell

(1993) and Haines (1994), to two to four years for each

model run. The enhanced simulation times should allow

analysis of the maintenance of currents and eddies as well

as the generation of these features.

10

50-

47.5-IN Columbia River

1: 45 - ccC-CUC

w42.50- DC

'40 -

Pon ConceptionM 35

IC

32.5-SCE

30--140 -135 -130 -125 -120 -115 -110

Longitude (degrees west)

Figure 2.1 Generalized circulation schematic of theCalifornia Current System (CCS). The broad, slow surfaceequatorward California Current (CC) overlies the polewardCalifornia Undercurrent (CUC) along with the Inshore Current(IC), also known as the Davidson Current (DC), SouthernCalifornia Countercurrent (SCC), and Southern CaliforniaEddy (SCE).

11

128OW 126 W 124 0 W 122 0 W

:.... .. Cape Mendocino

4()0 N-

Point Arena

+41

• 38 N"- -" San Francisco

.....................

..........

Monterey

Figure 2.2 Section of California Current System withschematized positions of jets and synoptic-scale eddies; C,cyclonic eddy; A, anticyclonic eddy. Arrows indicateprincipal surface flows; solid arrows are definite and openarrows are inferential. Also shown is a qualitativeanalysis of satellite infrared image gray shades for sea-surface temperature (SST) predominant patterns on 1 August1982: coolest SST, crosses; warmest SST, dots (from Mooersand Robinson, 1984).

12

50-

47.5- • •Columbia River

:: 45 0 0 " 0 0

0w 42.5LM• Cape Mendicino

"0

"a,

Point Conceptionm 35, •

3 2 .5 - • -

30--140 -135 -130 -125 -120 -115 -110

Longitude (degrees west)

Figure 2.3 Domain of model off the western coast of theUnited States of America. Domain bounded by 350 to 47.50 Nand from the coast to 12.5 degrees offshore. Model coversan area 1024 km (1408 km) in the cross-shore (alongshore)direction and the cross-shore (alongshore) horizontalresolution is 8 km (11 km).

13

Vb .

Hickey

Su,. .• . •. S.

' % -40.

Wickham et &I

St3*

14

;-

Figure 2.4 Map of a portion of the west coast of NorthAmerica, showing the location of some of the past studies inthe CCS (from Huyer r& al, 1989).

14

a Atmospheric PressureH

(mb)/05

.60-04

02.5

Figure 2.5Logermanamospheric pressure a e eeformb (a)Z Jaur5n b uy fo ue18)

15

'0i ; .II

16IDw

161C L

kl , A - - -

Figure~ 2. Logtr 15 -17)ma id tes(ye*m2 byoedge0qaefo hprprs(esn

1977).~~~~~~~~~~~ Cotuscrrsodt ontn antue f05

1.0,~~~~~~ ~ ~ ~ an 1. ye m2 ra hr h idsrs xed

1. dne c -2ar sadd frm.....193)

16-~~ - . ~,

Figure 2.7 An illustration of the distributions of keyproperties involved in the teleconnection process during atypical 91 Nifto-Southern Oscillation event. (Left) Uppertroposphere anomalies of geopotential height for theNorthern Hemisphere winter. (Right) Contours of surfacebarometric pressure, with surface wind anomalies (arrows) inthe tropics (from Enfield, 1989).

17

111. MODEL DESCRIPTION AND EXPERIMNfTAL DESIGN

A. MODEL DESCRIPTION

1. Basic Model

The model used in this research is a slightly

modified version of that used by Batteen et al. (1989, 1992)

which was adapted from Haney's (1974, 1985) closed basin

model. This limited area EBC model is multi-level, uses

non-adiabatic primitive equations on a P plane, and has both

barotropic and baroclinic components. The following

approximations are made: hydrostatic, Boussinesq, and rigid

lid. (For a more detailed summary of the model and the

governing equations, refer to Batteen r& al. (1989)).

2. Friction

The type of diffusion used can be important for the

generation of mesoscale eddies. Biharmonic rather than

Laplacian lateral heat and momentum diffusion is used in

this study. The use of biharmonic lateral diffusion allows

mesoscale eddy generation via barotropic (horizontal-shear)

or baroclinic (vertical-shear) instability mechanisms, or

both, as Holland (1978) and Holland and Batteen (1986) have

shown. The biharmonic coefficients are the same (i.e., 2.0

X 1017 cm4 s"1) as used in Batteen e= al. (1989). Weak (0.5

cm2s"1 ) vertical eddy viscosities and conductivity are used.

19

A simplified quadratic drag law is used to parameterize

bottom stress (Weatherly, 1972).

3. Boundary Conditions

The domain of the model on the eastern boundary is

closed and is modeled as a straight, vertical wall. A no-

slip condition on the alongshcre velocity is used. The

kinematic boundary condition of no flow through the eastern

boundary is imposed on the cross-shore velocity component.

A modified version of the radiation boundary conditions of

Camerlengo and O'Brien (1980) is used for the open

boundaries to the south, west, and north.

At the surface, the rigid lid approximation filters

out external gravity waves and allows a longer time step.

On the ocean bottom, no vertical heat flux or vertical

velocity is allowed.

4. Domain and Resolution

The domain of the model is an elbow shaped region

off California's coast from 350 N to 42.50 N as shown in

Figure 2.3. This covers an area 1408 km alongshore and 1024

km in the cross-shore direction. The horizontal resolution

is 8 km in the cross-shore direction and 11 km in the

alongshore direction. Mesoscale features within the CCS

should be resolvable with this resolution because typical

eddy wavelengths are around 100 km (Breaker and Mooers,

1986). Bottom topography and variations in the coastline

20

have been omitted to focus on the role played by wind

forcing in the CCS.

5. Finite Difference Schme

A staggered grid model, using the Arakawa and Lamb

(1977) B-scheme is used in the horizontal. Variables are

defined as follows: u, v, and w are velocity components

eastward, northward and vertical, respectively, t denotes

time, T is temperature, p is density, p is pressure, and

is the streamfunction. The center of each grid point

defines u and v while T, p, 4, w, and p are defined at the

corners. The B-scheme is used because it gives a superior

representation of the geostrophic adjustment process

(Batteen and Han, 1981).

The model uses ten layers in the vertical, with

constant z-levels at depths of: 13, 46, 98, 182, 316, 529,

870, 1416, 2283, and 3656 m. This spacing scheme

concentrates more layers above the thermocline in the

dynamically active portion of the ocean, consistent with

Haney (1974). Variables are staggered in the vertical with

u, v, p, and T defined at each level, while w and p are

defined between the levels which lie between the ocean

surface (w%-0) and at the bottom (z--H, where H is the

depth). A Matsuno time step followed by ten leapfrog time

steps is used and continuously repeated during the model

run.

21

6. Method of Solution

The method of solution is straightforward with the

rigid lid and flat bottom assumption because the vertically

integrated horizontal velocity is subsequently non-

divergent. The vertical mean flow can be described by a

streamfunction 0 which can be predicted from the vorticity

equation, while the vertical shear currents can be predicted

after the vertical mean flow is subtracted from the original

equations. The other variables T, p, w, and p can be

explicitly obtained from the thermodynamic energy equation,

equation of state, continuity equation, and hydrostatic

relation, respectively.

7. Initial Conditions

An exponential temperature profile with a vertical

length scale of h-450 m is used as the initial mean

stratification. The bottom temperature is assumed to be 20

C and the change in temperature between the bottom and

surface is 130 C. This profile was derived by Blumberg and

Mellor (1987) and has been used by Batteen (1989) and

Batteen et al. (1989).

B. WIND AND ATMOSPMEIC FORCING

The winds used to force the model are from the European

Centre for Medium-Range Weather Forecasts (ECMWF) (Trenberth

r& al., 1990) and have been provided by the National Center

for Atmospheric Research (NCAR). Winds were extracted from

22

world wide mean monthly wind velocities that were provided

at 2.5 degree spacing for the years 1980 to 1989 along with

120 month climatology for the area of study. This data was

linearly interpolated in space and then in time to provide

daily forcing at the desired grid points.

The total heat flux across the surface is initially set

to zero by choosing an initial air temperature that forces

the net flux of longwave radiation, sensible heat, and

latent heat to zero, as in Batteen e= al. (1989). The air

temperature is then used in the model. Any subsequent

surface heat flux forcing is thus a secondary effect of the

changes to SST due to the wind and/or thermal structure of

the ocean.

C. SPECIFIC EXPERIMENTAL DESIGN

Climatological winds were used for 365 days (Experiment

1) and then used to restart the model to run climatological

winds for another 365 days (Experiment 4). Next, 1981 winds

were run for 365 days (Experiment 2) and used to initialize

the run of 365 days with 1982 winds (Experiment 5). Then

1983 winds from a cold restart were run for 365 days

(Experiment 3) and then used to initialize the run of 366

days (leap year) with 1984 winds (Experiment 6). Two

additional extended runs were conducted in which the model

ran for four years. Experiment 7 used the climatological

23

winds four times, while Experiment 8 used the monthly winds

of 1981 through 1984.

D. ENERGY ANALYSIS T3CZNIQUZS

The energy technique used is the same as that used and

described in Batteen et al. (1992), and is based on that of

Han (1975) and Semtner and Mintz (1977). This is done to

gain a better understanding of the flow within the CCS and

of the types of energy transfer during unstable flow. A

brief summary of the method follows.

Kinetic energy (K) is calculated for the horizontal

components. After quasi-steady state is reached where the

total kinetic energy is nearly constant, mean and eddy

kinetic energies are calculated using the averaged sum of

squared mean and eddy horizontal fields, respectively.

Next, the available potential energy is calculated and used

to determine when a quasi-steady state is reached and when

statistics should be collected. Then, both mean and eddy

available potential energy are computed.

The energy transfers follow that of Semtner and Mintz

(1977), and are used to argue for the type of instability

mechanism (e.g., barotropic, baroclinic, or mixed) which

leads to the initial eddy generation in each experiment.

24

IV. RESULTS OF EXPERIUMTS

Experiments 1 through 3 study the effects of forcing a

model ocean domain that is initially at rest. Experiment 1

uses monthly climatological average (1980 - 1989) wind

fields, while Experiments 2 and 3 use monthly average wind

fields for 1981 and 1983, respectively. Experiments 4

through 6 study the effects of forcing a model domain that

has been spun up by the wind field from the previous year.

Experiment 4 uses the results of Experiment 1 as the start

for a second year of climatological average wind fields,

while Experiment 5 and 6 use the results of Experiment 2 and

3 as the start for 1982 and 1984, respectively. Experiments

7 and 8 use the results of longer (4-year) time runs from

climatological and 1981 - 1984 wind fields, respectively, to

examine the maintenance of features after initial spin up.

A. EXPERIMENTS STARTED FRC( REST

1. Experiment 1 - Climatological Winds

Experiment 1 was forced with monthly averaged

climatological (1980 - 1989) winds. Figure 4.1 depicts the

monthly wind patterns over the model domain starting with

January 15 (day 15) and ending on December 15 (day 345).

The atmospheric pressure pattern for January has a low to

the north and a high to the south which results in a wind

25

divergence near 400 N (Figure 4.1a). This pattern of

poleward winds north of 400 N and equatorward winds to the

south, continues through February and March (Figures 4.1b

and c). During April and May (Figures 4.1d and e), the

divergence in the wind flow is observed to migrate poleward.

By June (Figure 4.1f), an equatorward component in the wind

field is observed along the entire model domain. July,

August, and September (Figures 4.1g through i) depict the

strongest and most equatorward winds. By October (Figure

4.1j), the winds start to weaken throughout the domain and a

divergence in the wind flow is observed in the north. This

divergent wind flow pattern continues through November

(Figure 4.1k). By December (Figure 4.11) the wind

divergence has returned to around 400 N.

In response to the prevailing poleward winds in the

north, a relatively weak poleward coastal surface current of

-3 cm s-1 was observed by model day 30 (Figure 4.2). It

retreated further northward until by day 60 (not shown) it

was not discernible. An equatorward surface current was

observed along most of the coast by model day 90 (Figure

4.3) due to the prevailing equatorward winds over most of

the model domain. A poleward undercurrent, caused by the

meridional variation of the wind field (Batteen etal.,

1989), first became evident at model day 60 (Figure 4.4),

and was fully established by model day 90 (Figure 4.5).

26

Along with the equatorward surface current,

upwelling also occurred and was discernible by day 120

(Figure 4.6). Meanders in the equatorward surface current

formed by model day 210 and are evident in both the velocity

and temperature contour plots (Figures 4.7 and 4.8,

respectively). By model day 240, meanders began to form

cold core, cyclonic eddies as seen in the temperature

contour and velocity plots (Figures 4.9 and 4.10,

respectively) due to vertical and/or horizontal shear

instabilities between the equatorward jet and the poleward

undercurrent. The eddies initially appear to be about 30 km

(Rossby radius of deformation) in diameter and extend about

100 km off the coast, and appear during the period of

maximum wind stress (July - September).

The coldest temperatures due to upwelling were

reached by model day 240. After model day 270 no upwelling

was discernible (not shown). At the end of the year,

meanders and eddies in a weak equatorward surface current

were still present (Figures 4.11 and 4.12). A very weak

poleward coastal surface current (not shown), and a poleward

undercurrent were also present at the end of the year

(Figure 4.13). Note that no filaments developed during this

first climatological year.

Except for the lack of development of filaments,

these model results are consistent with available

observations cited in the literature. For example, the

27

eddies have rotational velocities of around 50-80 cm s-1

which is in agreement with observations of Mooers and

Robinson (1984). The poleward undercurrent is relatively

weak (-5 cm s-1 or less) and is in agreement with available

observations by Huyer e= al. (1989).

A time series of total kinetic energy per unit mass

over the entire domain is shown in Figure 4.14. In this

figure there are around three periods when the kinetic

energy becomes quasi-steady. These time frames correspond

to model days: 207 - 216, 228 - 231, and 297 - 303. Since

meanders and/or eddies appeared during these time periods,

more detailed analysis was performed on these intervals to

determine the type of instability mechanism that could

generate these features. Barotropic instability can result

from horizontal shiar while baroclinic instability can

result from vertical s,•ear in the current. As Figure 4.12

shows, there is considerable horizontal and vertical shear

between the equatorward surface current and the poleward

undercurrent. As a result, both types of instabilities

(mixed), can be present simultaneously. Energy transfer

calculations which consist of barotropic (mean kinetic

energy to eddy kinetic energy) and baroclinic (eddy

potential energy to eddy kinetic energy) components were

performed on the three time frames above.

The results for the instability analyses for these

periods are summarized in Table 4.1 (see Appendix A for the

28

energy transfer plots for this experiment), and show the

following: For model days 207 to 216, 228 to 231, and 297

to 303 both barotropic and baroclinic (i.e., mixed)

instabilities were present in the coastal, equatorward

region of the domain. Additional analysis of model days 297

to 303 shows barotropic instabilities to be weak (Figure

A.5) and baroclinic instabilities to be dominant (Figure

A.6) during this period.

2. Experiment 2 - 1981 Winds

Experiment 2 was forced with the monthly ECMWF winds

from 1981. Figure 4.15 depicts the monthly wind patterns

within the model domain starting with January and running

through December. Unlike the climatological winds, January

starts off with poleward flow throughout the model domain

(Figure 4.15a). February (Figure 4.15b) shows the typical

wind divergence at 400 N, consistent with the climatological

data. March through June (Figures 4.15c through f) depict

the wind divergence moving poleward and also shows the wind

speed increasing to a maximum in June, especially in the

southern half of the region. Figures 4.15g and h (July and

August) depict strong winds and equatorward flow throughout

the model domain. By September (Figure 4.15i), the wind

divergence reappears in the north and migrates equatorward

over the remaining three months of the year (Figures 4.15J

to 1). By December the wind divergence is at 37.50 N

29

(Figure 4.151), which is around 2.50 farther equatorward

than the climatological wind divergence.

As in Experiment 1, a relatively weak poleward

coastal surface flow -2 cm s-1 was observed in the poleward

region of the model domain (Figure 4.16). In response to

the wind pattern, an equatorward surface current was

observed along most of the coast by model day 90 (Figure

4.17). A weak poleward undercurrent became evident by model

day 90 (Figure 4.18), and became as large as 5 cm s-1 in

layer 5 (316 m) by day 210 (Figure 4.19).

Upwelling of temperatures cooler than 150 C was

observed by model day 120 (as observed in the climatological

run), as seen in Figure 4.20. Meanders in the surface

current also formed by the same model day as in the

climatological run (day 210) as depicted in the velocity and

temperature contour plots (Figures 4.21 and 4.22,

respectively). By model day 270, the first sign of eddies

appear (see the velocity and temperature contour plots of

Figures 4.23 and 4.24), which is -30 days later than in the

climatological run. The amplitude of the meander of the

coastal current increases to the south as a result of the

stronger equatorward winds in this region. Again, these

eddies are cold core, cyclonic, and about 30 km in diameter.

Upwelling of the coldest surface water oc-urred by

model day 240 (not shown), corresponding to the period of

strongest equatorward winds. Upwelling did not disappear

30

until model day 330 (not shown), which is -60 days later

than the climatological results. At the end of the year,

meanders in the equatorward surface current along with

embedded eddies remain (Figure 4.25). A poleward

undercurrent is also discernible at the end of the year

(Figure 4.26). A very weak poleward coastal surface current

(not shown) has reappeared in the poleward region of the

model domain. As in Experiment 1, no filaments developed

during this experiment.

Figure 4.27 shows the time series of total kinetic

energy per unit mass over the entire domain for 1981 and

shows four periods when the kinetic energy becomes quasi-

steady, model days: 210 - 222, 240 - 252, 297 - 303, and

309 - 333. Energy transfer plots were obtained for these

periods and yielded mixed (i.e., both barotropic and

baroclinic) instabilities in all cases in the coastal,

equatorward region of the model domain. These results are

summarized in Table 4.1 (see Appendix B for the energy

transfer plots for this experiment). During the time frame

297 to 303, barotropic instability (Figure B.5) was much

greater than baroclinic (Figure B.6) instability.

3. EZxperiment 3 - 1983 Winds

Experiment 3 represents the El Nifto year of 1983 and

was forced with the monthly winds depicted in Figure 4.28

representing January through December. The year starts off

31

with predominantly poleward winds for the first three months

as seen in Figures 4.28a - c. April shows a change in the

wind pattern as equatorward winds are present throughout

(Figure 4.28d). These winds remain equatorward and

strengthen from May through September (Figures 4.28e -i).

The winds weaken in October (Figure 4.28j). A divergence in

the wind field appears near 380 N during November (Figure

4.28k) and remains through December (Figure 4.281).

In response to the three consistent months of strong

poleward winds at the start of 1983, a poleward coastal

surface current with velocities as high as 5 cm s-1 is

established by model day 30 (Figure 4.29) and remains

through model day 60 (not shown). By model day 120 an

equatorward surface current develops along most of the coast

(Figure 4.30). A weak poleward undercurrent is present at

model day 90 as seen in Figure 4.31, and strengthens to

around 6 cm s-1 by model day 195 (not shown).

Upwelling and meanders both appear by model day 150

(Figure 4.32). The meanders are also discernible in the

velocity plot (Figure 4.33). Note that the meanders appear

farther poleward than in the previous experiments. Eddies

start to form by model day 240 as seen in the velocity

(Figure 4.34) and temperature (Figure 4.35) fields. As in

the previous experiments, these eddies are cold core and

cyclonic.

32

The coldest upwelling temperatures were reached by

model day 240 but were warmer (only 14.00 C as compared to

13.50 C and 11.50 C for climatology and 1981, respectively)

than observed in previous runs. No upwelling was

discernible after model day 270. By the end of the year,

meanders in the equatorward surface current along with

embedded eddies (Figure 4.36), a weak poleward coastal

current (not shown), and a poleward undercurrent (Figure

4.37) were discernible. As in the previous experiments, no

filaments developed during the experiment.

Figures 4.38a and b show the time series of total

kinetic energy per unit mass for 1983. Quasi-steady periods

that prompted additional evaluation were, model days: 186 -

192, 222 - 234, 249 - 258, 279 - 288, 312 - 315, 324 - 327,

and 342 348. The results for the instability analysis for

this year are summarized in Table 4.1 (see Appendix C for

the energy transfer plots). Every period showed mixed (both

barotropic and baroclinic) instabilities to be present. The

instability analysis for model day 279 to 288 was the only

case where one type of instability was noticeably greater

than the other, and in this case barotropic (Figure C.7) was

greater than baroclinic (Figure C.8).

4. Sumary of First Year Run Results

Table 4.2 summarizes the climatological, 1981, and

1983 experiment runs for the first year. In all first year

33

runs, both a surface equatorward current and a poleward

undercurrent developed. There was also a poleward coastal

surface current present during the winter season. Upwelling

was a seasonal feature which, as expected, had the coolest

temperatures during a non-El Niflo year (1981) and warmest

temperatures during an El Niflo year (1983). Both meanders

and eddies were generated. The eddies were cold core,

cyclonic, and had a size around the Rossby radius of

deformation (30 km). Along with an equatorward surface

current, both meanders and eddies remained at the end of

each year. Instability analyses revealed that both

barotropic and baroclinic processes were important eddy

generatiol. mechanisms. In all first year runs, no filaments

were observed.

B. EXPERIMENTS SPUN UP FROM THE PREVIOUS YEAR

1. Experiment 4 - Climatological Windu

Experiment 4 was forced with the same monthly

averaged climatological winds as in Experiment 1 (Figure

4.1). In this experiment, the model was continued with the

spun-up output from Experiment 1, rather than starting from

rest. For convenience this experiment is referred to as

'Climo III because climatological winds are used a second

time.

In response to the wind forcing, an equatorward

surface current was observed by model day 396 (year day (yd)

34

30) (Figure 4.39). Embedded in this current are meanders

and cyclonic eddies (Figures 4.39 and 4.40). A weak

poleward coastal surface current was also present initially

(not shown). A poleward undercurrent was established by

model day 426 (yd 60) (Figure 4.41).

Upwelling was observed by model day 546 (yd 180)

(Figure 4.42), and peaked by model day 606 (yd 240) (Figure

4.43), with a minimum temperature near 120 C. Cessation of

upwelling occurred by model day 726 (yd 360) (not shown).

In previous model runs anticyclonic meanders were

observed, but they did not close off to form anticyclonic

eddies. During this experiment, in addition to the

predominantly cyclonic eddies, a warm core anticyclonic eddy

(defined by closed contour in streamline plot - not shown)

formed by model day 456 (yd 90) (Figure 4.44). This

anticyclonic eddy persisted for the remainder of the year.

Figure 4.45 is a cross section in the middle of the

domain and depicts the broad meanders in the CC along with a

strong core of the CUC near 250 m in depth. Between model

days 696 (yd 330) and 726 (yd 360), an eddy formed as the

result of a pinched-off meander (Figures 4.46 and 4.47). A

filament was observed during this experiment by day 606 (yd

240) and extended about 300 km offshore (15i C isotherm)

near 40* N (Figure 4.43).


over the entire domain is shown in Figure 4.48. Four

35

periods were investigated further because the kinetic energy

became quasi-steady. These time frames correspond to model

days: 378 - 408 (yd 12 - 42), 453 - 465 (yd 87 - 99), 504 -

516 (yd 138 - 150), and 624 - 636 (yd 258 - 270). All four

of these periods consisted of both barotropic and baroclinic

instabilities. These results are summarized in Table 4.3

(see Appendix D for the energy transfer plots for this

experiment).

2. Experiment 5 - 1982 Winds

Experiment 5 was forced with monthly winds from

1982. This experiment continues the spun up case using the

output of Experiment 2 (1981) as a starting point, rather

than starting from rest. Figure 4.49 shows the monthly wind

patterns within the model domain starting with January and

running through December. January starts with the typical

divergent flow, this year slightly to the north at 420 N

(Figure 4.49a). February moves the divergence equatorward

to 400 N and has weaker winds to the south (Figure 4.49b).

The flow in March is onshore throughout the model domain

with a slight poleward component in the north (Figure

4.49c). April has the divergence at 42.50 N (Figure 4.49d).

May starts the all equatorward flow and is the strongest

(Figwue 4.49e), this regime continues in June (Figure 4.49f)

through October (Figure 4.49i). A divergent flow returns in

October at 42.50 N (Figure 4.49j), and migrates equatorward

36

to 38.50 N in November (Figure 4.49k) and remains in

December (Figure 4.491).

As in the previous experiment, the year starts with

a fully developed equatorward surface current which contains

embedded meanders and eddies (Figure 4.50). Also present is

an anticyclonic eddy, and a poleward surface coastal current

in the northern part of the model domain (Figures 4.50 and

4.51). A relatively strong (-9.5 cm s-1) poleward

undercurrent is present by model day 426 (yd 60). A cross

section in the middle of the domain (Figure 4.52) shows this

feature along with a strong subsurface flow associated with

an eddy (Figure 4.53).

Upwelling began by model day 516 (yd 150) (Figure

4.54), and peaked by model day 606 (yd 240) (Figure 4.55).

The coolest water observed was around 12.00 C. The

upwelling ceased by model day 696 (yd 330) (Figure 4.56).

Four cyclonic eddies and one anticyclonic eddy were

preser. e.g., Figure 4.53) throughout most of this

experiment. The size ranged between 30 and 150 km in

diameter and the westward propagation of these larger

features was around 500 km. As in Experiment 4, a filament

was observed during this experiment. By day 600 (yd 234)

(not shown) this filament extended about 350 km offshore

near 38.50 N. A cold core eddy pinched off from this

filament by day 606 (yd 240) (Figure 4.55).

37


over the entire domain was produced (Figure 4.57), and

showed two quasi-steady periods for additional study. These

were model days: 507 - 516 (yd 141 - 150), and 525 - 528

(yd 159 - 162). As in the previous experiments, the energy

transfer plots indicate the presence of both barotropic and

baroclinic instabilities. Table 4.3 summarizes these

results (see Appendix E for the energy transfer plots for

this experiment).

3. Experiment 6 - 1984 Winda

Experiment 6 was forced with monthly winds from

1984. This experiment continues the spun-up case using the

output of Experiment 3 (1983) as a starting point, rather

than starting from rest. Figure 4.58 shows the monthly wind

patterns within the model domain starting with January and

running through December. January has a divergent flow at

430 N (Figure 4.58a), while February shows that the

divergence has moved equatorward to 398 N (Figure 4.58b).

From March through May (Figures 4.58c through e), the wind

divergence moves from 410 N to 430 N and the winds become

stronger. June is the start of equatorward wind flow

(Figure 4.58f), which continues through July and August

(Figures 4.58g and h). In September, the wind divergence

reappears in the north at 470 N (Figure 4.58i). During

October and November, the divergence migrates equatorward to

38

370 N (Figures 4.58i and k). The year ends in December with

weak winds along the coast with a divergence at 400 N, and

with predominantly equatorward winds further off the coast

(Figure 4.581).

At the start of the experiment, there is a well-

developed equatorward surface flow with embedded meanders

and eddies (Figure 4.59). There is also a weak poleward

coastal surface current in the northern corner of the model

domain which remains until model day 426 (yd 60) (Figure

4.60). A relatively strong (-10 cm s-3) poleward

undercurrent is evident, as seen in a cross-section in the

middle of the model domain, at model day 546 (yd 180)

(Figure 4.61).

Upwelling begins by model day 456 (yd 90) (Figure

4.62). Corresponding to the period of maximum equatorward

winds, the peak occurs at model day 576 (yd 210) (Figure

4.63) in which cooler temperatures of around 100 C are

present along the entire coast. This year had upwelling of

cooler water earlier than previous years and also had the

coldest water which was a result of the strong equatorward

winds. Cessation of the cooler water occurs by model day

726 (yd 360) (not shown).

The eddies are around 90 km in diameter and stay

within 300 km of the coast. A filament occurs by model day

666 (yd 300) (Figure 4.64). This filament is observed near

39

380 N as a plume of 150 C wateL .id extends about 200 km off

the coast.

The time series plot of total kinetic energy per

unit mass over the entire domain is shown in Figure 4.65.

The kinetic energy is still fluctuating because the model is

still spinning up during the first part of the year. Three

periods were selected for additional study, model days: 576

- 591 (yd 210 - 225), 606 - 624 (yd 240 - 258), and 645 -

657 (yd 279 - 291). All of these included both barotropic

and baroclinic instabilities, and are sunmnarized in Table

4.3 (see Appendix F for the energy transfer plots for this

experiment).

4. Summary of Second Year Run Results

Table 4.4 summarizes the follow-on (second year)

model runs. In general, a weak coastal poleward surface

current was evident during the winter season in the northern

region of the domain for all years (Climo II, 1982 and

1984). A meandering equatorward surface current, already

present, at the start of these experiments was maintained.

A poleward undercurrent was generated in all experiments.

The eddies, already present at the start of the experiments,

were both cold core, cyclonic, and warm core, anticyclonic

eddies in Climo II and 1982, while in 1984 there were only

cold core, cyclonic eddies. The size and offshore extent of

the eddies were consistent with the first experimental runs.

40

Seasonal upwelling occurred with minimum temperatures of

-120 C for Climo II and 1982, and of -100 C for 1984. The

year 1964 had the largest extent of cool upwelled water as

expected for a year with the strongest equatorward winds.

Filaments developed in all three experiments, but was most

pronounced (as expected) in 1984. The filaments had an

offshore extent between 200 and 350 km. Instability

analyses revealed that both barotropic and baroclinic

processes were involved in eddy generation.

5. Experiment 7 - Multiple Climatological Runs

Experiment 7 was an extended climatological run in

which the climatological winds used in Experiment 1 (Figure

4.1) were used in repetition four times. The third and

fourth years of the run follow Experiment 4 (Climo II) and

are dubbed "Climo III" and "Climo IV", respectively. (The

values in the model on the last day of a run were retained

for use at the start of the next run, rather than starting

from scratch or rest as is done in a cold restart.)


surface current was observed by model day 760 and 1125 (yd

30) for Climo III and Climo IV, respectively (not shown).

Embedded in this current were meanders and cyclonic eddies

(not shown). A weak poleward coastal surface current was

also present initially (not shown). A poleward undercurrent

41

was evident early on by model day 820 and 1185 (yd 60) for

Climn III and Climo IV, respectively (not shown).

Upwelling was observed by model day 850 and 1215 (yd

120) for Climn III and Climo IV, respectively (not shown).

The upwelling peaked by model day 970 (yd 240) for Clima III

(not shown) and day 1305 (yd 210) for Clima IV (not shown),

with a minimum temperature near 110 C. Cessation of

upwelling occurred by model day 1060 (yd 330) for Clime III

(not shown), and was still present in small patches by day

1455 (yd 360) for Climo IV (not shown).

Figure 4.66 and 4.67 show the total kinetic energy

per unit mass time series over the entire domain for Climeo

III and Clime IV, respectively. Climn III has a peak

kinetic energy of 166 cm2s"2 around model day 915 (yd 185)

while Climo IV has a peak of 145 cM22s 2 at model day 1293

(yd 198). Figure 4.68 depicts the total kinetic energy per

unit mass time series for all four ciimatological runs

together. It clearly shows that the first and second runs

were involved in the generation or spin-up of features in

the model, while the third and fourth runs oscillated about

125 cm-2s 2 and indicate the maintenance of these features

(i.e., a quasi-steady state).

6. Experiment 8 - Multiple Years (1981 - 1984)

Experiment 8 was a run of two additional years of

the model using the monthly winds of 1983 (Figure 4.28) and

42

1984 (Figure 4.58). This experiment differs from Experiment

3 (1983) which was started from scratch (cold restart). The

runs in this experiment followed in succession after

Experiment 5 (1982), and used the values in the model on the

last day of the year as input to the restart.


surface current was observed by model day 760 and 1125 (yd

30) for 1983 and 1984, respectively (not shown). Embedded

in this current were meanders and cyclonic eddies (not

shown). A weak poleward coastal surface current was also

present initially (not shown). A poleward undercurrent was

evident by model day 820 and 1185 (yd 60) for 1983 and 1984,

respectively (not shown).

Upwelling was observed by model day 880 (yd 150) for

1983 (not shown), and day 1155 (yd 60) for 1984 (not shown).

The upwelling peaked by model day 940 and 1305 (yd 210) for

1983 and 1984, respectively (not shown). The minimum

temperature was near 110 C for both 1983 and 1984, but 1983

had only patches of this water while 1984 had this cool

water along the entire coast. Upwelling was still present

in small patches by day 1090 and 1455 (yd 360) for 1983 and

1984, respectively (not shown).

Figure 4.69 and 4.70 are the total kinetic energy

per unit mass time series over the entire domain for 1983

and 1984, respectively. The year 1983 has a peak kinetic

energy of 128 cm2 s" 2 around model day 963 (yd 233) and 1984

43

has a peak of 215 cm2s" 2 at model day 1368 (yd 273). Figure

4.71 depicts the runs for all four years (1981 through 1984)

together on one total kinetic energy per unit mass time

series. It appears that the first year (1981) as seen in

Experiment 2 and the second year (1982) as seen in

Experiment 5, were involved in generation or spinning up of

the model. The third year (1983), which was an El Nifto

year, had an energy level on par with 1982, so that no

increase in kinetic energy occurred. In the fourth year

(1984), the energy level increase significantly to the

highest value (215 cm2s' 2 ). Comparing this figure to the

climatological time series (Figure 4.68) for the last two

years shows that the maximum (1984) and minimum (1983)

kinetic energies lie on either side (as expected) of the

climatological year. During a non-El Nifo year, as is 1984,

features such as equatorward currents and upwelling would

strengthen while during an El Nifo year, as in 1983, these

features would be weaker.

7. Sumary of Multiple Year Run Results

Table 4.5 summarizes the last two years of the

extended (four year) runs. Listed here are Climo IV, 1983,

and 1984. Similar results are obtained: A poleward coastal

surface current, a surface equatorward current, a poleward

undercurrent, along with embedded meanders and eddies. Of

interest, upwelling occurs later in 1983 (at yd 150) than

44

for the other years (yd 60 to yd 90). Although the minimum

temperature is the same (11.00 C) for all years, 1984

experienced a larger area of cooler water (all along the

coast) than that of the El Nifio (1983) year. In all

experiments, there were both cold and warm core eddies.

Finally, filaments were observed during Climo IV and 1984,

but not during 1983.

45

TABLE 4.1 SUMMARY OF INSTABILITIES FOR CLIMATOLOGICAL YEAR(TOP), 1981 (CENTER), AND 1983 (BOTTOM).

MODEL DAYS FEATURE TYPE INSTABILITY LOCATIONfor (Meander, (Barotropic, (Coastal,

Climatology Eddy, Both) Baroclinic, Offshore,Mixed) Both)

207-216 Meander Mixed Coastal

228-231 Meander Mixed Both

297-303 Both Mixed Both


1981 Eddy, Both) Baroclinic, Offshore,Mixed) Both)














46

TABLE 4.2 SUMMARY OF EXPERIMENTS - FIRST YEAR.

FEATURE CLIMO 1981 1983

Sfc Poleward -1-60, & -1-60, & -1-60, &330-360 days 330-360 days 330-360 days

Sfc Equatorward -90 days -90 days -120 days

Undercurrent -60 days -120 days -60 days(poleward only)

UPWELLING:(<15 o C) ___

Start -120 days -120 days -150 days

Maximum -240 days -240 days -240 days(min temp) (13.00 C) (11.00 C) (14.00 C)

Cessation -270 days -330 days -270 days


EDDIES:_______


Core cold cold cold

Rotation cyclonic cyclonic cyclonic

Size (diameter) -30-60 km -30-60 km -30-80 km

FILAMENTS:

Start none none none

Offshore n/a n/a n/aextent

47

TABLE 4.3 SUMMARY OF INSTABILITIES FOR CLIMATOLOGICAL II YEAR(TOP), 1982 (CENTER), AND 1984 (BOTTOM).


Climo II Eddy, Both) Baroclinic, Offshore,Mixed) Both)

378-408 Both Mixed Both(12-42)

453-465 Meander Mixed Coastal(87-99)

504-516 Both .xed Both(138-150)





525-528 Both Mixed Both(159-162) _





645-657 Meander Mixed Coastal(279 -291)

48

TABLE 4.4 SUMMARY OF EXPERIMENTS SECOND YEAR.

FEATURE CLIKO II 1982 1984

CURRIENTSSfc Poleward -366-426 -366-426 -366-426

(1-60), & (1-60), & (1-60), &696-726 696-726 696-726(330-360) (330-360) (330-360)days days days

Sfc Equatorward -396 days -396 days -396 days(30) (30) (30)

Undercurrent -426 days -426 days -546 days(poleward only) (60) (60) (180)

UPWELLING:(<15 0 c) CStart -546 days -516 days -456 days

(180) (150) (90)

Maximum -606 days -606 days -576 days(min temp) (240) (240) (210)

(12.00 C) (12.00 C) (10.00 C)

Cessation -726 days -696 days -726 daysMANDRS: (360) (330) (360)

Start -396 days -396 days -396 days(30) (30) (30)


Core cold & warm cold & warm cold

Rotation cyclonic & cyclonic & cyclonicanticyclonic anticyclonic


FILAMENTS:


Offshore -300 km -350 km -200 kmextent

49

TABLE 4.5 SUMMARY OF EXPERIMENTS - MULTIPLE YEARS.

FEATURE CLIKO IV 1983 1984

CURRENTS: _______, _______ .... __,__,,,_,,

Sfc Poleward -1096-1215 -731-850 -1096-1185(1-120), & (1-120), & (1-90), &1395-1455 1060-1090 1425-1455(300-360) (330-360) (330-360)days days days

Sfc Equatorward -1125 days -760 days -1125 days_,_(30) (30) (30)

Undercurrent -1155 days -790 days -1155 days(poleward only) (60) (60) (60)

UPWELLING:(<15 o C)


Maximum -1305 days -940 days -1305 days(min temp) (210) (210) (210)

(11.00 C) (11.00 C) (11.00 C)

Cessation -1455 days -1090 days -1455 days(360) (360) (360)

MEANDERS: ______________


EDDIES:.______. __. ___ ___._________ _______.____. _

Start -1125 days -760 days -1125 daysI_(30) (30) (30)

Core cold & warm cold & warm cold & warm

Rotation cyclonic & cyclonic & cyclonic &Ianticyclonic anticyclonic anticyclonic


FILAMENTS:

Start -1305 days none -1305 days(210) (210)

Offshore -350 km n/a -350 kmextent

50

:imo (OfRO fig) Winds - day 1% Climn (11160- N0) Winds day 4!.

/////// / I I I l!,/ / , .,- / / ,

/1 / / / / / , F I / I , .9,-, / I 1li ' 4 110l1. 4

771 , / / / / , / , , 77(1 / , ." 9 I , •

77 0 'p77A

S,, / / , , -. -. . . .. . 9/,, - - .. . .

76E, /" - , - 66.. - -.. .

I 9 -ý . . . - -, " - - 'q \

l.4 22.3 43.7 69.8 86.3 187.7 129.a 1.9 77.3 43.7 65. 116 1 16? 7 12"1 i

-limo (19R(0-6) Winds. -day 75 Clima (1980 119) Winds day 105

20.0 I/u

•161 4 113.4.-*-" t .-" - /" -. - 9" 9 / /

77 1 77 1

5, , . . . . • ,

-" - N. \\\ \ \ \ \.

7'!. .. . "• \ \ 266 *

Longitude Longitude

Figure 4.1 Mid-monthly averaged climatological (19801989) ECMWF winds in m s- : (a) January, (b) February, (c)March, (d) April, (e) May, (f) June, (g) July, (h) August,(i) September, (j) October, (k) November, and (1) December.The latitudinal grid point 1 (129) corresponds to 350 N(47.50 N); so that the latitudinal grid point of 52corresponds to 400 N. Maximum wind vector is 20 m s"1.

51

Clmro (1980 69) Winds day 135 Clina (19060 - ) Winds -day 166

i~~~'9~ 1 29 -8

18:1 4 183.4

52 2 522-

2b 26 6

I . 22 V\ 3.7 N 6%. \6\ Vi' 7 1 9 1 ý 1 6. 63%' )

-- * Clinso (1980- 89) Winds -day 195 Clirna (1980-89) Winds -day 225MAXIMMUIO20.0 r/

1111 4 103A4

7/ 0 17.8-

12? 52,2-

26 6 26 6-

6 223 13 V~ a--6\ 221~6~~ r', 'i \I,0o1giLude longitude

Figure 4. 1 (continiued).

52

CInto (1980 89) Winds -day 255 Chima (1980 so) Winds -day 285

IY a. A- -A1

16.1 4 133 4

,, II 17 II

92 2 52 2

SI ' \ \ \" , ,,

26 6 26 6-

i j \ \ \ 1 \ \

.1 22.3 43. P 6 .0 86.3 197 1 1298

- Clino (1980 89) Winds -day 315 CIrnoo (1980-BO) Winds -day 345MXINUM "INDS

20.0 U/S

129 a -- *. I. I , A. 129.6- J-- ..- L -. _.... _

1011 4 163.4-

26 6;26 6

' " .'" -,- '-, ., -• ' - ; A , " / ' /'- '-* - • • - • - , '/ "

;02 3 43 7 65 a 0. 3 1 8 129 0 M 22 3 43 7 65.6 ofý 3 lei 7 1 ý) a

Longitude Logiaitude

Figure 4. 1 (continued).

53

Distance off shore (km)

-1324.3 -953.3 -692.7 -512.3 -341.3 -173.7 3.3

140P.9- I I I 1. - -

0

-- - - -. _---

1173.3--- ,-

•'a "-- -- k....

0"I -

214.7- ,',";-

S* II--- I"'. I,

0 .8 " "

Figre4.2 Exeiet1 uraemrdoalcmoeto

0J ' +,1

C,,1 I I l,,

+ w vlc69y3 $7 -he -

I,,,

*It'llli g"II*

?)34 . 7 - |% -l iiI •

L II.11.1IIIIlgIp

IRorth-South vel contour at. model day 30.0 'I

Figure 4.2 Experiment 1: Surface meridional component ofvelocity at day 30. The contour interval is 1 cms.'. Thedashed lines indicate equatorward velocities. The maximumpoleward velocity is -3 cm s"1* Latitudinal alongshoredistance 0 (1408) km corresponds to 350 N (47.50 N).

54

Distance off shore (kin)

-1024.0 -853.3 -682.7 -512.1 -341.3 -170.7 8.0

1409.0 - I I

1173.3-

939.7 -

0m 784.8-

to93

-U 469.3-

2344.7 -

Velocity at model day 90.0

Figure 4.3 Experiment 1: Surface velocity vectors at day90. To avoid clutter, velocity vectors are plotted at everythird grid point in both the cross-shore and alongshoredirection, and velocities less than 5 cm s1 are notplotted.

55


-1024,6 -853.3 -682.7 -512.6 -341.3 -170.7 6.6

0.0- .! t..-- . --. -H ,s

-151 .6l-H~me I.I,, I• it

- 302.1 - Ras

-453.1 (J-€• -694.2-- L-.Im

-755.2-

- • 6 3 -I!II1

-1024.0 -953.3 -692.7 -512.6 -341.3 -117.7 6.9

North-South velocity at model day 60.0

Figure 4.4 Experiment 1: Cross-section at y-704 km

(41.250 N) of the meridional component of velocity at day60. Dashed lines indicate equatorward flow, while solidlines indicate poleward flow.

56

Distance off shore (km)-1024.0 -,53.3 -682.7 -512..8 -341.3 -1,7N.7 @Ae

'.9-- I I. I I

I I -o

-151 .0-

-102.1 , --

- 604.2 -

-1824.8 -853.3 -682.7 -512.6 -341.3 -170.7 6.,

North-Sotith velocity at model day 90.0

Figure 4.5 Experiment 1: Cross-section at y-704 km(41.250 N) of the meridional component of velocity at day90. Dashed lines indicate equatorward flow, while solidlines indicate poleward flow.

57


-1524.9 -953.3 -692.7 -512.3 -341.3 -175.7 U.6

146• . I I It

1173.3- 18

q38.7-

0I~k g18

A 704.0-

0

C.)

•-- 469.3-M t8

234.7-

"18

Temperature contour at model day 120.0

Figure 4.6 Experiment 1: Surface temperature at day 120.The contour interval is 10 C. The temperature decreasestowards the coast.

58

DisLance off shore (kin)

-1924.0 -853.3 -682.7 -512.9 -341.3 -17.7 F..

1438.9- _________ ___

1173.3- I

III

I

936.7 II

I

II.

U3I

/

4J 49.31.7- I0 /

.74.3-

o / / I"--I, 1/ 1

U)/I /1 1Imi i n

4-' 469..'3-

i1/I II//// I

I /1/1/ I

/ IlI

Fiue4.7- IEI S i -

210 ToI avi ltevlctvcosaepotda

II IllII/ II/ III

/1 II ~II

Velocity at. model day 210.0 ***

Figure 4.7 Experiment 1: Surface velocity vectors at day210. To avoid clutter, velocity vectors are plotted atevery third grid point in both the cross-shore andalongshore direction, and velocities less than 5 cm s-1 arenot plotted. Note start of meander at y-500 km.

59


-1024.0 -n53.3 -682.7 -512.fl -341.3 -170f.7 0.9

1 173.3-

'130. 7 -

0)

• 7014.0J --

o

-• 469.3--

~j4 4

PIA. 7 --

' 1 8

e. - t I_ __t1


Figure 4.8 Experiment 1: Surface temperature at day 210.The contour interval is 10 C. The temperature decreasestowards the coast. Note start of meander at y-500 km.

60


-1024.0 -8A 3 3 -682.7 -512.0 -341.3 -170.7 0.9

II I ! I

1173.3-

9138.7 -

t•t0 .4

13

00

234 .7-

14

18-


Figure 4.9 Experiment 1: Surface temperature at day 240.The contour interval is 10 C. The temperature decreasestowards the coast. Note the formation of cold core eddy aty-230 km.

61

Distance off shore (k1m)

-1824.0 -B53.3 -682.7 -512.0 -341.3 .170.7 O.R

M40N 0- I I -

IIII

II

1171.3- ! -

IISII

II''II

938.7- II

U, III3o €/11

Veoct at4. moedy24.

oe "f c ec

20 as in Fiue43 oetefrmto fcl oeed

i/// ! "m t/1/I

at y-2.30-k. The/ nube asoitdwth o ty70k

'/// /

/41

I37 II ,k

I I

I~ I,1 " -

Velocity .t. model day 240.0 2u•_,ln*XIMI• vrf flnn

Figure 4.10 Experiment 1: Surface velocity vectors at day240 as in Figure 4.3. Note the formation of cold core eddyat y~230 km. The number associated with the low at y-700 kmcorresponds to temperature, not velocity.

62


-1024.0 -853.3 -682.7 -512.0 -341 .3 -170.7 8.8

14(nR1 P- -I I___

1173 1-

9n.7 -

0J1 704.0-to•

00A69.3-

0.8-


Figure 4.11 Experiment 1: Surface temperature at day 360.The contour interval is 10 C. Note meanders and eddies arestill discernible in temperature contours.

63


[email protected] -953.3 -682.7 -512.0 -341.3 -179.7 3.0

143ne0- ! I I IIII

I II

'i Ii

1171.3- 1

toI

4697,.3- I

II,,I

3.7- IIIII,

liVc ay

"Al-.O ilr iol

o I,

II!

II

III"

III 1

Velocity at model day 360.0 ._

Figure 4.12 Experiment 1: Surface velocity vectors at day360 as in Figure 4.3. Note equatorward surface current overa poleward undercurrent. The number associated with the lowat y-800 km corresponds to temperature, not velocity.

64


-1024.9 -953.3 -692.7 -512.8 -341.3 -17F.7 0.

- " " " ' - 4 . 1" -

I- . " - "0- .' "

-~~ 79. -

-151. - 5.7 - . ,341. -170.7 a"." ""S-' " " - " I

,- -392.1 -- -"" .8 , " ' J -

F-i43. - Ex. 10

co -6 oyt. 2 - 3 e-

- 795.2 -

-99e6.3 - I I'

-1924.9 -953.3 -692.7 -512.9 -341.3 -179.7 9;.9

North-South velocity &t model day 360.0

Figure 4.13 Experiment 1: Cross-section of the meridionalcomponent of velocity at dlay 360. Note meanders and eddiesare still discernible in a weak equatorward surface current.

65

Kinetic Energy vs. Time65 1T TT-- I 1 I 1

60

55

45

- 40 -(V

U* 35

N,

'2 io

• 25

15

0 50 lo 150 200 250 300 391 4AS

Time (days)

Figure 4.14 Experiment 1: Total kinetic energy per unitmass time series for climatological (1980-1989) year overthe entire domain (Units of the kinetic energy are cm2 s 2 ).

66

101 Winds -day 15 Io 111u, 1 • ,l..y 45

'• ~ t t t I I o • . .- .- ," / ,"I /

1/ 1t " "A /m/ ,7'I

CO ~ < ' < 4 1 r T Ai * i~ ' " , VP /

a b

' / /1 / I 4 / ,,

20/ ,, , / / / / .. . 0--,

10 14 10:1 4

-1 P

26

C IS

I0 2) 1 41 1 ,', 0 oil, 1 1l, , i r 0 21 ., 1 0- -0I !g i l a id e 1

a tii l d y

Figure 4.15 Mid-monthly ECMWF winds for 1981 in m a-1:(a) January, (b) February, (c) March, (d) April, (e) May,(f) June, (g) July, (h) August, (i) September, (j) October,(k) November, and (1) December. The latitudinal grid point1 (129) corresponds to 350 N (47.50 N); so that thelatitudinal grid point of 52 corresponds to 400 N. Maximumwind vector is 20 m a1

67

1961 Winds day 135. 19111 Winds day 16,5

.#1 Il 1! I , I , I I , *• l I * I * I , I I ,

* - , .. , • . P _ t • . • . • ..

191 14 191 4

eI

i1tl 1 4 1111 4

' 4 I 1I II

_• ..... . .\ \ \ \ \ . .- ,-, \ \ \ \

266

---- ÷ IIl0l Win~ds day 195 I198l Winls day 22."i)MAZIU WIITNIHDS

20.0 u/ul

. iiiii11 t , \ \ \\\\ \\ \

LO,)•tucleI~ongitudc

Figure 4.15 (continued).

68

.9111! widl day 255 1901, Wilds ?M,) •II!:

l~ ' l • I , I I I *a I , I * I

--. \,, \ \ \ ",10 1 4 I101 4

6 2)6 6

- ... ~ 19011 Winds day :115 10111 Winds day :1I5HAXIMMU WINIDS

20.0 u/O

101 4 181 4

* -. -. \ \ \ .. .. \/,, /\ \ \ / / / /

.......... ,-\ \. \ \/ -... ... ,A,, \ //,/,/

)f, 6 ~~~16 b '- - - -

I 3 411 6, 0 .161 I Is? 129 14 2)3 4:1 1 6 ',a 1163 Is/ I

lo.n1git wi c 1igtudc


69


-M124.0 -853.3 -682.7 -512.0 -341.3 -17f 7 8.014 80e.0 - U o It I1I ,I~ _

1173,3- --

0 -.

0

00t /• ~ ~ " - II

0 Loi •-, 0../

I 0It

7946 . --..- ,I --

o I.,i

"I"

234.7 -. I,,

!'.,

'i,

North-South vel contour at model day 45.0

Figure 4.16 Experiment 2: Surface meridional component ofvelocity at day 45. The contour interval is 1 cm s"-. Thedashed lines indicate equatorward velocities. The maximumpoleward velocity is -2 cm s-1. Latitudinal alongshoredistance 0 (1408) km corresponds to 350 N (47.50 N).

70


-1,24., -853.3 -682.7 -512.3 -341 .3 -17f.7 0.0

1173.3-

q38. 7 --

S704.8-- 1 _In

469. 3-

.7- 1--

0.0-

Velocity at model day 90.0 _0IJl kmllI- VrIOIne

Figure 4.17 Experiment 2: Surface velocity vectors at day90. To avoid cluLter, velocity vectors are plotted at everythird grid point in both the cross-shore and alongshoredirection, and velocities less than 5 cm s"- are notplotted.

71


-1024.0 -653.3 -682.7 -512.0 -341.3 -171.7 5.6S* -• - - -" - -°Ia . . lIo . . . "

~lI.8 - - . e -. - - I1.g -- .-

-151."5 L-... La, -

,,• -453.1I

S~L-.tel .t L_.n _.4. -1 4 2

-604.2- L.* k.k. k,

-755.2-

-1024.5 -853.3 -682.7 -512.8 -341.3 -175.7 9.A


Figure 4.18 Experiment 2: Crcss-section at y-704 km(41.250 N) of the meridional component of velocity at day90. Dashed lines indicate equatorward flow, while solidlines indicate poleward flow. Note weak polewardundercurrent.

72


-1824.0 -853.3 -682.7 -512.3 -341.3 -170 7 0.0

148. I

1174 .3 -

234. 7 -

III

0.0-4.0 -

II

- 49,37 - 91 -


Figure 4.19 Experiment 2: Layer 5 (316 m) velocity vectorsat day 210. The maximum poleward velocity is 5 cm s'l neary-469 )an.

73


-1324.3 -893.3 -692.7 -512.3 -341.3 -176.7 a.V

1408.3- I I I

1173.3-

0WI.9 704.0g--

tM

0-4

0a

469.3--U,,

234 . 7

•.9 - - -


Figure 4.20 Experiment 2: Surface temperature at day 120.The contour interval is 10 C. The temperature decreasestowards the coast.

74


192.4,0 -853 3 -682.7 -512.6 -341.3 -170 7 3

In 7

liIivi'iII

'II'IIIIII

S,''I

oi/

0 ,

V/ /,,S// /ll

0

U ///' Jill

4 f7/- - /suIo.' -/ ----- I

,,A7-/1/"l//Il.... I

'1/]/// llit'' -I1//I- 11111

I///i/ III


wlll f InsPl

Figure 4.21 Experiment 2: Surface velocity vectors at day

210. Note the meander near y-469 kIm.

75


1074 a -RC3,1 1 -682 7 -,17 I -341 3 179 7 9.0

- /70or

apaId

Vu

t14 2 _ N I 2


Figure 4.22 Experiment 2: Surface temperature at day 210.The contour interval is 10 C. The temperature decreasestowards the coast. Note the meander near y-469 km.

76

l)Ist•, o ff shore (km)

"1C4 ll 60 1. -341 3 -173.7 0.6

I In P L - I II-IIIIII,Ii

1~II IiIiIfIIII

'II

-

o I -

Vlct att moe a 7..

SI

corespnd to tepraue not veoiy.Ntteed

/1/I I

Ill,/// II

lii

I II //| II

III, / 11

SI'll' I

corrspods t teperaure not velo ity Noe h ed

near y-600 km.

77


-1024.0 -893.3 -602.7 -512.0 -341 .3 -170.7 ".0

1408 .- - I RI _

1173.3-

Q•R. 7-

0704 P-

ol

h 469,3-

714 7 - S .-

e.g,- I B"


Figure 4.24 Experiment 2: Surface temperature at day 270.The contour interval is 10 C. The temperature decreasestowards the coast. Note the cold core eddy near y-6000 km.

78

Distance off shore (kin)-102•4.0J -853.3 -682.7 -512•.9 -341 .3 -170.7 @•."

140 .0 -- !-- ---I I ,

fqem

1173A.3-

I H

918.7-

469.1-It

M

C18

IT

2•.14.7 - !, •


Figure 4.25 Experiment 2: Surface temperature at day 360.The contour interval isn 1 C. The temperature decreasestowards the coast. Note existence of meanders and embeddededdies.

79


-1824.1 -953.3 -692.7 -512.0 -341.3 -173.7 3.0

',,.O .' -.1,, , *.

-- 3o - - * - l

-. '1S2 I --. 8" -"S-453.1 -0 - _

II

-76 3- -n n--1324.3 -853.3 -632.7 -512.3 -341.3 -173.7 3.6

North-South velocity et model day 360.0

Figure 4.26 Rxperiment 2: Cross-section at y- 7 04 kin(41.250 N) of the meridional component of velocity at day360. Dashed lines indicate equatorward flow, while solidlines indicate poleward flow. Note existence of polewardundercurrent.

so

K;netic Energy vs. Time

• -

60

U 50(V

N

U 40

w

10 -

0 so IN• 15 2M 291 190• 4A

Tline WAlY"l

Figure 4.27 Experiment 2: Total kinetic energy per unitmass time series for 1981 over the entire domain (Units ofthe kinetic energy are m2s92} . Quasi-steady periods: days210-222, 240-252, 297-303, and 309-333.

81

190:1 Wsinds day 16 1983 Winds day 45

'" /1/1 /1 /11 1'/;1 11 1 1/ // // // /ll / 33 / / /1 /1111I 1

""////////i¢ "9//I//f IiIu:1

9

36 ,'///i /,,,. 36 7/ 1/////1/ ,. * / 5 , ,2 /

a b

a 22 3 43 7 65 0 86 3 17.1 .1393 1.0 22.3 43.7 65.3 06.3 107 1;2299

MAITUM ... . 1 1:1 "i14S day 75 190 Wilnds day 105

20.0 I/a

t2l 0 1,| • j .| j I • L "129 .__I -- |.._L_..... L_-i _A I

\ i I

I 1 I I I I l Ii -

292 4 923.4

r I-I I 1 1. N \

S~,,ii,,i/ I I,,

\S \ \ \S \s \. \. S

.. //dI'\ \ \ \ \ \ \

.-. 5,

03- .. a.A.. '# 7/ /" /r , -'-"23 • • ,

2 2 3 43 1 (5 8 06 3 101 7 239 6 2 2.3 43.1 65 0 06 3 10? 1 129 0

lzngitudc loigi-tude

Figure 4.28 Mid-monthly ECMWF winds for 1983 in m 9'1:(a) January, (b) February, (c) March, (dý April, (e) May,

(f) June, (g) July, (h) August, (i) September, (j) October,

(k) November, and (1) December. The latitudinal grid point

1 (129) corresponds to 350 N (47.50 N); so that the

latitudinal grid point of 52 corresponds to 400 N. Maximum

wind vector is 20 m s".

82

1903 Winds --day 135 19N3 Winds day 165

- -\ \ \ \ 12 .

I1I 4 163 4

- N -. -\ -. -. -, "

IU 0 17.8

'i) 292 2

26 6 26.6

0 f

- 1983 Winds -day 195 1986 Winds day 225KA13I4UK WINDS

20.0 0/-

18:3 4 10e: 4

a -- --'- '..'.'. \ ',. \ ',, N, ', \ \ \ \ \ \ \' \0 1

• .",.\ \ \\\ ',\\ \ \\ \ \ \ \ -

26,6 26.6,.,•, \\\ \\ \., ,,, \ \ \\\\\\\ .

1 ... 6 ?Al j.' 7\ 8 8% 0 9 22t -3,7V X ,. 8

i~oigitudc ~LonglLude


83

108:1 Wlind --day 255 1903 Wields day 2115

-,\ \ \\\ \ t '18:1 4 161 4

", \\ \ \ I I I . . .

52 2

1 2273-'j431 F .0O 8N7 2 9 1.0 2

9 22.3 43.a

-~1903 Winds -day 315 1983 Winds day 345KaZZNM~ WINDS20.0 .1.a

* I \ ., I £ 1.I.I *i~ I * 129 L.L.L'..L . .8 I a.

*I -- t--,- -// I I I I I I I I ,

123 4 183.4

/)9 -. ~~ ~ / / / 1 77 8 .

v

S2 ;1 SP 2.A / I- . - . -

26 6 26 6-;

-" - P" -- I- -. .. 1.0 - - A .

26 7- -+: J: -•. •o: -" 6- --'- -,-- +-v ,- t -+, ,.

11 22.3 43,7 65.0 86.3 lf? 7 129 1 . 22,3 43.7 615.0 .b 3 -17.i 1 i 0

Longitude longitude


84


-102A4. -853.3 -682.7 -512.1 -341.3 -17N.7 ".a

117M 3--

qrnl. 7 -

Ix

140

0

g.

-~469.3-

234.7 -

9.9-

Velocity at model day 30.0 _M_2._MAXlI MIIM ¥V"W'W I I

Figure 4.29 Experiment 3: Surface velocity vectors at day30. To avoid clutter, velocity vectors are plotted at everythird grid point in both the cross-shore and alongshoredirection, and velocities less than 5 cm s-1 are notplotted. Note poleward flow to the north of y-1200 km.

85


-1624.0 -853.3 -682.7 -512.1 -341.3 -171.7 P.A

140n.e- I I I I

1173.3-

')9f1 . 7 -

0I

0

7141I-UI"

.-2 I

o) IC) I

469.3-

S~I

34•7- I

Velocity at nodel day 120.0HA•lg-m, vrftnn

Figure 4.30 Experiment 3: Surface velocity vectors at day120. To avoid clutter, velocity vectors are plotted atevery third grid point in both the cross-shore andalongshore direction, and velocities less than 5 cm a-' arenot plotted. Note equatorward surface current dominates.The number associated with the high at y-250 km correspondsto temperature, not velocity.

86


-,924.9) -653.3 -682.7 -512.8 -341.3 -179.7 @.P"-- ""- -'- '-"" I • % -,

-151 ,@ -A.0- II.oO .

-• - 43 . I - .1 _

-453.1- I.

L-.,4

•799. 2 - -..

-1024.0 -853.3 -682.7 -512.9 -341.3 -170.7 @.A


Figure 4.31 Experiment 3: Cross-section at y-70 4 km(41.250 N) of the meridional component of velocity at day90. Dashed lines indicate equatorward flow, while solidlines indicate poleward flow.

87

DIstance off shore (km)

,ga4 a OKI 3 62 7 5i1 0 -34d1 3 170 7 I.9

14pfl . . I . .. _ ........ A- -

1171 1

"7.18 7 -

I,",

LO0

MA 7R4.R -

0)

()

41 469.3-

034.7 -7


Figure 4.32 Experiment 3: Surface temperature at day 150.The contour interval is 1° C. The temperature decreasestowards the coast. Note the existence of upwelling andmeanders.

88


t 824 p _953 . -,2 7 -S12 3 3d' 3 li 7 36

II

140RI 9 - '-

A 70490--

II-

in0

IdI

0

0

274 .7 -

9.9-


Figure 4.33 Experiment 3: Surface velocity vectors at day150. To avoid clutter, velocity vectors are plotted atevery third grid point in both the cross-shore andalongshore direction, and velocities less than 5 cm sa arenot plotted. The number associated with the high at y-850km corresponds to temperature, not velocity. Note themeanders near y-938 km.

89


1974 li60 1 67 7 S12 6 341 3 170 7 P S

140" 0

11171 1

SIII'III

II

153fl 7 '1II'I

III'I,

lis

6) III

'4 III

W'I

0.Fiur 4.4 Eprmet3 ufcevlct lecosa a

2 . T olo

km/ ce

o /i/ -

./ I//Ji

Ill Il

Io d I de

II 9

Velocity at model day 240.0__,___,

Figure 4.34 Experiment 3: Surface velocity vectors at day240. To avoid clutter, velocity vectors are plotted atevery third grid point in both the cross-shore andalongshore direction, and velocities less than 5 cm s"I arenot plotted. The number associated with the high at y- 2 50km corresponds to temperature, not velocity. Note existenceof eddies.

90


-1624.9 -953 3 -682.7 -512.8 -341.3 -1W7 7 .6

4 0. 8 -- - -I I I I I

11 71.3-

g .q0.7 -

70 46to

00

69.3-

214.7-1I:

" .6 - I


Figure 4.35 Experiment 3: Surface temperature at day 240.The contour interval is 10 C. The temperature decreasestowards the coast. Note existence of eddies.

91

D)istance off shore (kin)

-1624. -853.3 -682.7 -512.6 -341.3 -171.7 1.1

468.8- I ! I I

1173 1-

0

0 I

469.3 --

IBIs

FU r- 18T ------ IAL


Figure 4.36 Experiment 3: Surface temperature at day 360.The contour interval is 10 C. The temperature decreasestowards the coast. Note eddies remain at end of year.

92

Distance off shore (km)-1324.3 -953.3 -692.7 -512.9 -341.3 -17N.7 S.A

- 3•. 3I-i v- • I ;l~ .,_'. -"

, . - - .- ,.,

-S • ' V , -

R-O I -.

151 . 11- 1W-

0 -R4.S2 -

-9053.---r

- I I•

-124 .9 -t953.3 -62.7 -512.3 -341.3 -173.7 3.9

North-Soft~h velocity at model day 360.0

Figure 4.37 Experiment 3: Cross-section at y-704 km(41.250 N) of the meridional component of velocity at day360. Dashed lines indicate equatorward flow, while solidlines indicate poleward flow. Note poleward undercurrentremains at end of year.

93

Kinetic Energy vs. Time

4C-

40F

319

NNUU

2• 5

9~

N

N

U

w 20

15-

F 20 40 60 80 100 120 140 160 180 200 220 240 260 2FS 300 320

Time (days)

Figure 4.38a Experiment 3: Total kinetic energy per unitmass time series for 1983 (days 1-306) over the entiredomain (Units of the kinetic energy are cm2 s- 2 ). Quasi-steady periods: days 186-192, 222-234, 249-258, and 279-288.

94

K;nelic Energy vs. Time5'.5 -rTI i-r~vtl--t v | v w -r , ' •vI vv I v' w I i , I--rfr• --- v t |r -ii

5-.

49 9

F

US

' 49.0

LLJ

N

4 6 . 9 1 1 u_ I -JL-L I _. .J I _ L I -i - i t- t i I I i , i I t i I I i i i I i t j 1- - i t , II L L JL L LI I I I I I L 1 I

306 316 326 336 346 356 366

Time (days)

Figure 4.38b Experiment 3: Total kinetic energy per unitmass time series for 1983 (days 309-363) over the entiredomain (Units of the kinetic energy are CM2g"2) . Quasi-steady periods: days 312-315, 324-327, and 342-348.

95


-1924. -9513 3 -682.7 -512.8i -341.,3 -171W 7 5.3

I ~I_____ -

111111tIl, I1111 I!111 I

toI

CI!

''I'II'•''ll l l

A69.13 -_

Fi1g 4.3- E 4 11

1111111/

atlt e third g po'n i b hor

alongshore direction, and velocities less than 5 cm s"I arenot plotted. The number associated with the low at y-80 kmcorresponds to temperature, not velocity. Note equatorward

surface current with embedded meanders and cyclonic eddies.

96


-1124.0 -853.3 -692.7 -512.9 -341.3 -178.7 0.9

14 03'e- I I I I -

11 73.3 -

934.7 -

W

in 7N .0 -

us 469.3--0

234.7 -


Figure 4.40 Experiment 4: Surface temperature at day 396(yd 30). The contour interval is lo C. The temperaturedecreases towards the coast. Note cold core eddies.

97


-1824.0 -953.3 -692.7 -512.0 -341.3 [email protected] 3.41.- i __ ...._ -.3- ,_- - -. f r-. -. '-- ,' . .. ,,, - u.. •./"-5"3 .-. . .. -j: --.,.

""" .-- . , ,,

- 5 5.2-. g,.-. -3112.1 - -. - , , -,,-

- - 5.*-- 14

-90l6.3 It_

4 J4

-1324.1 -853.3 -682.7 -5t2.0 -341.3 -173.7 3.3


Figure 4.41 Experiment 4: Cross-section at y-704 km(41.250 N) of the meridional component of velocity at day426 (yd 60). Dashed lines indicate equatorward flow, whilesolid lines indicate poleward flow. Note existence ofpoleward undercurrent.

98

Distance. off shore (k1m)

-1024.8 -853.3 -682.7 -512.0 -341 -17F.7 8.g

1480 a0-

1173.3-

10

930 7 -

to

0..

0

: 74.7-- I-


Figure 4.42 Experiment 4: Surface temperature at day 546(yd 180). The contour interval is 10 C. The temperaturedecreases towards the coast.

99

D)istance off shore (km)

-1024.0 -853.3 -682.7 -512.0 -341.3 -170.7 0.0

14 0.@- 1 . .-

18

1173.3-

ll8939.7-

0 -0

2.•.£7 • -

0S704.0o-

0

469.3 -8

234.7-14

Temperature contour at. model day 806.0


100


-1024.A -853.3 -682.7 -512,6 -341.3 -179.7 9.9•4999e- L... I !

AI

Velocity at tIoeldyI5IIAiWI IIio

lii II

1173.31 1 II

111Ill111 tit

1111 '\% I

at eerythir grd pint n bth he l crs-hr an

'Ill,

101|

-II-

SI I H1//)• -

o II I ,. •

0 I11//

*i 79I-I Il I i/

.2 11111 • I 1/

II 4693-- II

I ~iF- li\\

eI-.I I 1 -l -

Velocity atl model day 456.0 *SI..Ke2

Figure 4.44 Experiment 4: Surface velocity vectors at day456 (yd 90). To avoid clutter, velocity vectors are plottedat every third grid point in both the cross-shore andalongshore direction, and velocities less than 5 cm s1I arenot plotted. Note anticyclonic eddy at y-650 Iam.

101


-1324.3 -853.3 -692.7 -512.3 -341.3 -173.7 3.3

S-7I

o~- ... . Z : 2 98-o - - " "" •- *.

- 33. S-- .. - • -30 .'o, ,, ..-- '~I,'~ 3, -- _ ~ S ... -,,

S'. _- • - - - .4 - - -

,. -453...4..4

c'• -63)4.2•- -

- 755.? --

-9N6.3- _ _ _ _ _ _ _ _ _ _ _ _ _-8

-1024.3 -853.3 -682.7 -512.0 -341.3 -173.7 3.3


Figure 4.45 Experiment 4: Cross-section at y-704 km(41.250 N) of the meridional component of velocity at day666 (yd 300). Dashed lines indicate equatorward flow, whilesolid lines indicate poleward flow.

102


-1824.9 -85,.3 -682.7 -512.9 -341.3 -17".7 B."

149.8 9- I I I I 1 _20

1173.3-

93S.7 -

20

W11

0

V) . 20 lie_

o 1,,' to20

234.7- 1 ~m1

20 1 1 260 16


Figure 4.46 Experiment 4: Surface temperature at day 696(yd 330). The contour interval is 10 C. The temperaturedecreases towards the coast. Note formation of eddy frompinched off meander at y-469 km.

103


-1624.3 -853.3 -682.7 -512.6 -341.3 -170.7 6.6

1410.0- 118

1173.3-

938.7 -

Inoto

S469.3 -- lt,

'234,. 7 - i,.,

18j 16


Figure 4.47 Experiment 4: Surface temperature at day 726(yd 360). The contour interval is 10 C. The temperaturedecreases towards the coast. Note formation of eddy frompinched off meander at y-469 km.

104


130 " rr -T-- -T --

120

110

100

U

Y

7,

N

E

U -0

70-

60

• 0 * 1 t m t I t I t t I . I t ! | t I i I I |_ ._ _L I_

0 50 100 150 200 250 300 350 4V 0

Time Idays)

Figure 4.48 Experiment 4: Total kinetic energy per unitmass time series for Climo II over the entire domain (Unitsof the kinetic energy are cm2 s- 2 ). Quasi-steady periods:days 378-408 (yd 12-42), 453-465 (yd 87-89), 504-516 (yd138-150), and 624-636 (yd 258-270).

105

1012 Winds day 15 1962 Winds day 45

l < I2 I , 4 I- ,. - I -, - JI24 *I .. I.. .. 4 -__ 4. ... -n__ _, * , 4

S.. .. . ..... .. .. " - .. .. .. -. /" / / / /

• ,, ,_*.. _.. . . .. .. -A ... .. . -" .- / / / /181 4 -113 4

ab

1 21 37 6.0 16. 3 117.7 129 8 1 I 22.3 43.7 65.8 86 3 197 7 129) I

-i 1982 Winds -- day 75 1982 Winds dny 105MAXIMUM4 WINDS

20.0 alo

1211 I 4* 129 a - ~ I. a I--

101 4 113 4

". \ \ N \ \ \ \ N '. N -.,

-, ,,, H\ \ 1.7 " "

21, 6 26 6-,, .

.5 \\ \ N \\\\\ \ . ....

a S S- \ \ \ \ \ \ \ \ N

Cd

1 0 22 3 41 7 69,I 86 3 17 11 29 I IiI 1 22,3 43 1 6568 06 3 107 1 129 I0

Longitude L~ongitude

Figure 4.49 Mid-monthly EMW winds for 1982 in m a(a) January, (b) February, (c) March, (d) April, (e) May,(f) June, (g) July, (h) August, (i) September, (j) October,(kc) November, and (1) December. The latitudinal grid point1 (129) corresponds to 350 N (47.50 N); so that thelatitudinal grid point of 52 corresponds to 400 N. Maximumwind vector is 20 m s-.

106

1042 Winds day 135 1962 winds day 165

113.4-" "\129 8-

l 1J 3 4Hll II II

S2 52.2

26 6

1942 Winds --day 195 38 ~d a 2

20.0 .=/&129• * . I 11-a- ---..-I ---.- .... --- -- L .--.--I---, --. 129.6l ---- ---J------'----I -- -- L--.j -i .a -I-

~i 'I129.

10: 4l 113.4

52 2 52.2

5 7 2 6 6

I6.12?L3 • E .• \ ,,\ ,..1?, ,,q, I -'" \ \I' A'"'66 ;\,6\ \aI\ '>'Iongitude Longitude


107

1982 Winds day 255 1982 Winds day 285

*\ \\ \\\ \ \ ,-N N N -. - o

IN:) 4 113 4

1I 8 77

S-., ---

52 2 52.?-

26 6 26.6-

. I I . .023 ,, 1 I 22.3 43.7 65.8 06.3 181.1 1"

1982 Winds -day 315 1902 Winds - day 345

20.0 ,/St29 II L _J _. - J _ -- - . . . I .. .L __ .. . 129.0 __ . - I.--. --- I - -.- I -. I --, - I -.*

-.... ... , I I / / / / / I/ III I

S. . . . - / I I / / / / / / / 1 !

113.4 163.4-- - - , 1 I' / / / , , / / / / ,

. .. . . . .- - / I / / / -p - / / / I I

.11 0 11.9--- - / I // / - -. -. - / / I I

"0- -- , / ~ / - .o / / l

a 1 0 !- -.- -I- - -I ý - - I-

•6 6*- .. 5 ,266 .. ..- /-

I a 22 3 43 7 6 6 9 06.3 17,7 1 129 I8 1a 22.3 43.7 65 I8 6.3 1 .7. 1;9 8qLongitude Longitude


108


-1024.9 -853.3 -682.7 -512.9 -341.3 -176.7 0.8'498.3-- I I !

4II

111 1 7 ,3 . 3 - | ii--

Los

'111 t1

alnshr drcio.7- eoctesls tuhan 5 m - r

II I'I'tI

t e u I I It ll

with po r sufc curntnrh1fy1173 k.-.,

10

S794.9- ut \

•0 ~III1IIlI

S~IIIll/11//11-I//ill /,

p37i/i I I~ ii~~11111/

II/III'

9.9-lt II F 4

Figre4.50Exeimn 5:I Sufc veoityecor atda

alongshre diretionndvlociie lestan5c s r

sufaeluren cith embde meaders and eddis,0aongK~

withupoeard0 suprfacen curen northc eof ty-7 km.os a

39 (d 0} T aoi cuter vlolt vctrsa109ote


-i924.0 -953.3 -692.7 -512.9 -341.3 -179.7 9.9

1499.9 *. I*.. -I

a aaI l IS

~ I

b I I p I ! "

. 40

469:.3-- ,q

* ' I 'I

%1 II•

-t 0

934.7- % .

-10i=. ', • '. a0'N ° ¶-1€

,*l - , o' ,,.

,c , , 30.o- , . .

7* ". a O ' 'I , -2 - * _/"

veoci. a0

8 . T e d s e i e in ic t e ut o r ve ci es Th

ma xi mu soe r ve o c ty i s -1 m - . L ti u i a

alnsoe ditac -( ket4

11~,,110

S 469.3- • 0 1 e L ; .20 , so -

-I ° I ; ** -I tO ; ; 0_ ' *' '- 0

I " 'I * -• • % II /|1 g

23 . - 0,,,, ' ,,_ -10-10 -10 1 1- 0

aximu polewar velot is -1 cm s Lattudna

aloguhre distancerien0 (108 Surfcorespelonds topo nen o4f5

N).

110


-1324.3 -953.3 -692.7 -512.3 -341.3 -173.7 3.3

,'.3- ," t ' -, , - , L_.m ,, __, Ie2a5 e - -. " •~ ""- .""• " '"-T';"••lI

-113 -8, -..• -p.8 ,'t tS., -" - , -.8, -,~2-f

__ -332.1 - - " 5 -"" -" " - 'i/t 'I' -.W-2

) - 42*3 192.1 -

A S.

-755.2- III' 4 1 -. 8. ;

-906.3

-1024.3 -853.3 -682.7 -512.3 -341.3 -173.7 3.N


Figure 4.52 Experiment 5: Cross-section at y-704 km(41.250 N) of the meridional component of velocity at day426 (yd 60). Dashed lines indicate equatorward flow, whilesolid lines indicate poleward flow. Note strong polewardundercurrent along with subsurface flow associated with aneddy.

111

Distance off slhore (km)

-1•24.3 -853.3 -682.7 -512.3 -341.3 -170.7 9.3

14M38- I I - _IllIlIl I

4J 693- 111 1111

I23 .Ii I I

iIl Il

I O 1 1WI 1W

notplote. Th nubr asoiae wit th low embedded

/112

II2 .. ~I"\

IllIlI -

734- I/I/I'

SII tl '

.26.MA/II/ vIini

Figue 4.53 Expeiment 5:SraevlctyvcosaIa

temeraure nt vlocty

I I1 I\ \"'112• il


-,•124. -1151.1 -682.7 -512.3 -341.3 17N.7 V.P

146 .- I I Ir- -

- 173.3-

a,0

fm



113


-1024.0 -893.3 -682.7 -512.8 -341.3 -170.7 ".0

40R.- I I I18

1171.1

08

938. 7-

54

L4o

00

I., I p -


Figure 4.55 Experiment 5: Surface temperature at day 606(yd 240). The contour interval in 10 C. The temperaturedecreases towards the coast. Note maximum extent ofupwelling.

114

Distance off shore (kim)

-1324.6 -853.3 -692.7 -512.9 -341.3 -179.7 8.0S• .-I , I I I I._

1400i.0- __ j - --

20

is

1173.3-

20

4 37 . 70-

to

0

+j 469.3 -( -

02

d m.n

234.7-

6.9-


Figure 4.56 Experiment 5: Surface temperature at day 696(yd 330). The contour interval is 10 C. The temperaturedecreases towards the coast. Note the disappearance ofwater cooler than 150 C.

115

Kinetic Energy vs. Time1•~~~~~~~~~~~~~~ I- Ii•V I v w v-r- r-T- --- 7-T v-

125

120

115

NN

135

785

F1 so 100 159 200 250 3F 190 Ape

Time (dlays)I

Figure 4.57 Experiment 5: Total kinetic energy per unitmass time series for 1982 over the entire domain (Units ofthe kinetic energy are cm28-2). Quasi-steady periods: days507-516 (yd 141-150), and 525-528 (yd 159-162).

116

1911.1 Winds day 16 1984 Wind. day 46

)11* I ,-a .-. .. . . . I A" I I * I

"101 4 1I:1 4

/1 I/A.... . ,$$/9/P7//// I!

•ll / / - - \ \ o i. i A,-/ I I - I /

,-• * ' " \ \ I I / • / i ... .. I .. - ,

a , I1 \\\ I b ...

143 i.IIO6X3' 1 1) " . 1

2,3 3. a. 22.3 43.7 659 86.3 9. V I?9 II

MAI -- 19114 Winds -day 75 1l84 Wiedn day 105W4ar I J1'H NDS

20.0 0/n

/ / / / / / / / / / / .... •, • . .. .. .. . .

1I.l 4 113 4/ / ,' -9 . / / / / ....~ , ... .. .. . .. ...

/'/19 i 7---. /" A / / i"I I I.,_, . ......... . .

it II 77.11

,• '• " -.. .. .- -. -, - ,,,, /-

S -- . . .. .. -. ...\.\..N,,,\ \ \ N.

26 6 .. 26.

C d1' .q I \ .' 111 N 1"I a. , 1 '\ ' 'IX , . ,., ,,

IN 22 3 43.7 6i 8 06 ei 9 1 1 2 3I~ongi~I Ic I~ioniltuidc

Figure 4.58 Mid-monthly ECMWF winds for 1984 in m a'1:(a) January, (b) February, (c) March, (d) April, (e) May,(f) June, (g) July, (h) August, (i) September, (j) October,(k) November, and (1) December. The latitudinal grid point1 (129) corresponds to 350 N (47.50 N); so that thelatitudinal grid point of 52 corresponds to 400 N. Maximumwind vector is 20 m sa-.

117

£964 Willit -day 135 1084 Winds day 165

-. ~~~~ ~~ I - A A - - . -. - . * -. -

113 4 10:1 4

~1 a

5 2 57.?

26 6 26 6

~ I I--~ 1 -££-I~rrr~w~ r'.'1 2 "WI 6 1% 1.a 22. i3. 6\.Ia\86\ 1l2 A

NAINN IN 1 904 Winds -day 195 1984 Wsinds day 225

20.0 0/0

a ~1 -A-.a.....s.i *~~i* 129.0

10:1 4 101. 4

71l 11''~i t 11.0

9

Logitd Log~d

/11 l~\118

1884 Winds day 255 IO4 Winds -day 18

I•'I l .* -l. ._ - --J. l. -. N . _ L -_ ~ .. \ *-- -. - . , _I _, I , i

A. -A . -. - -

101 4 13 4

I) 8 11.0

112 52.2

26 6 26.6

I \ \\\\\\ ' \ \\ \

22. 3 FIr 6ý 11%1 0 1 g 22 ~ 3 77 X '0; 06' i ) 1964 Winds day 315""IKiUHlll KlINDS 1984 Winds -day 345

20.0 u/a

1 29 0 - .- l-J . _ L -. _.L . 12 9 .0 - _. LJJ I L . L L L. ._ _ _

-.. ... -.-.. .. -.. / / I I• /

103 4 1634

11 A - / / /77.8.-

k 1U 'N. . N.\ \ \ \ '

: . ,/ /i2 - •" .,. 2, *. • .. I-..-.- - 52

-*61 ... -b•I • - *"P-- .-'fr -#

\ \\ \ \ \ \ \

1 22 3 43 1 653 86.3 137.7 129.1 . 2. . 67 , 06.3 I1s 7 129 a

Iongitude Longitude


119


-1024.1 -853.3 -682.7 -512.1 -341.3 -170. 7 M.1

1408.0- I !

1173.3- 111 1

9 3 e3.7 - I I / / 1_

Q) I IIIk, III /I

0

937-Ill '~<

S~~ ~~I I I I /...-.-..

U, I , a•'40

A 469 .3 ---

.III I _ ,

234.7- 11 -• II II I, / •t I • \" I I "_-_,________.

I

Velocity at model day 396.0HAXm q "s .vrflin

Figure 4.59 Experiment 6: Surface velocity vectors at day396 (yd 30). To avoid clutter, velocity vectors are plottedat every third grid point in both the cross-shore andalongshore direction, and velocities less than 5 cm s-1 arenot plotted. The numbers associated with the low and highembedded in the meanders and eddies along the coastcorrespond to temperature, not velocity. Note equatorwardsurface flow with embedded meanders and eddies.

120


-1•24.0 -95,.13 -682.7 -512.1 -341.3 -176.7 6.6

14U.R -I I , I I

0 -193P. -1

-0'.

I I

0 .

10* * I 0

6 I i 0 -

o , I P

o LU

% I tI •

234.7- / , ,'0fit'"•'"

L -.

SI -!0/," . , -'. "--' ",

"S.04 '- • - .. 0.s,.

/0

Not-ot vel cotu at mdelday:26.

S'. T veloie."I•9. - •, \ -| . , ' *, l

I 121

.- , . , - , , ,.--

, , , [ - ' -II 0 -" , ', -. I "• "-- , ,

* L." -- • 1 • l I- • ' '|I|S•, , -\ • . ... ., .,

o ,L. ' , '!X\ ,, , S , ",;..' /

S.... "-, ' ,,./ ."

North-South vet contour at model day 426.0

Figure 4.60 Experiment 6: Surface meridional component ofvelocity at day 426 (yd 60). The contour interval is 5 cms~z. The dashed lines indicate equatorward velocities.Latitudinal alongshore distance 0 (1408) km corresponds to350 N (47.50 N). Note weak poleward flow along the coastnorth of y-1273 km.

121


-1024.0 -853.3 -682.7 -512.0 -341.3 -170.7 a.0• . - .I I I.

010-

%

-

5

-- 3

S -453.1 -

76 5.•--

W * _'.1

14- 90. 3-. III

-1024.0 -853.3 -682.7 -512.0 -341.3 -170 7 .0

North-SouLh velocity at model day 546.0

Figure 4.61 Experiment 6: Cross-section at y-704 km(41.250 N) of the meridional component of velocity at day546 (yd 180). Dashed lines indicate equatorward flow, whilesolid lines indicate poleward flow. Note existence ofpoleward undercurrent.

122


-1924.0 -653.3 -682.7 -512.9 -341.3 -17N.7 0.0

1 173 .3 -

g398.7-

W,1.

0

In

0rd

S461).3 --

i-IP

1°.,.,


Figure 4.62 Experiment 6: Surface temperature at day 456(yd 90). The contour interval is 10 C. The temperaturedecreases towards the coast. Note start of upwelling.

123


-1024.0 -853.3 -682.7 -512.0 -341.3 -175.7 6.6

1460..- t -t

1173.3-

938. 7-I -

14

0)

to

00 1

0(d•

1.2

114734 .7-


Figure 4.63 Experiment 6: Surface temperature at day 576(yd 210). The contour interval is 10 C. The temperaturedecreases towards the coast. Note maximum extent ofupwelling.

124


[email protected] -853.3 -682.7 -512.. -341.3 -1 7. 7 1.1

14 M ). I ! I I a M

1171.3-

18

Q.18. 7 -

0704.0-

0

Is)

V3

4 '• - 1 ' I234.7 2814

16 i


Figure 4.64 Experiment 6: Surface temperature at day 666(yd 300). The contour interval is 1 C. The temperaturedecreases towards the coast. Note occurrence of filament aty-250 km.

125


160 -T--r--T--r---T-T -7 1 1 ' 1 v Y I I I ' I T -,r--T -

1405

1315

1205

N 111

U

F0

90

C" 115 -•

60

50

0 50 Ion 150 200 250 300 351 41

Time (days?

Figure 4.65 Experiment 6: Total kinetic energy per unitmass time series for 1984 over the entire domain (Units ofthe kinetic energy are cm2 s8 2 ). Quasi-steady periods: days576-591 (yd 210-225), 606-624 (yd 240-258), and 645-657 (yd279-291).

126

Kinetic Energy vs. Time170T ' '

S145Nw

U -

* 1/10

S135U

w'y 13•

125

119

7uge Iday~l

Figure 4.66 Experiment 7: Total kinetic energy per tinitmass time series for Climo III over the entire Jomain (Unitsof the kinetic energy are cm2 sg 2 ). Peak value of 166 cm2 s" 2

at day 915 (yd 185).

127

Kinelic Energy vs. Time190 -- -j I ' I I , I I I , I I I I p I I I I I I I I I ' - - - -

135

w 130N

105

US

(V 125N

EU

Iw~ 120 -

115-

110 -

10 5 -

WOO t I i I I ! I I l I I I I I I t I i t i I I I i I I I I ' i I I _ _I_

0 50 100 150 200 250 300 3:;S 109

Time (days)

Figure 4.67 Experiment 7: Total kinetic energy per unitmass time series fcr Climo IV over the entire domain (Unitsof the kinetic energy are cm2 8' 2 ). Peak value of 145 cm2 s" 2

at day 1293 (yd 198).

128

Total Kinetic Energy180-II

100 - - clihno,.cllno2

*. . climo3 I •

140 *. cnmoq ,p

I 4 91400

-120 '"<*

0 100-E

80-'U

/

40-

20-0

0 250 500 750 1000 1250 1500Time (day)

Figure 4.68 Experiment 7: Total kinetic energy per unitmass time series for Climo, Climo II, Climo III, and ClimoIV over the entire domain (Units of the kinetic energy arecm 2 9-2).

129

Kinetic Energy vs. Time1 1 0 1-r - - - T -- - , 1 1 1 1 V w V I I I I '-T '- - V ! r ' - I - "

125

119

u 110•U105

w

N

Y

95

9(

50 100 11W 200 251 305 350 41-IF

Time Idays)

Figure 4.69 Experiment 8: Total kinetic energy per unitmass time series for 1983 over the entire domain (Units ofthe kinetic energy are cm2s"21 . Peak value of 128 CM28-2 atday 963 (yd 233).

130

85 ~ I II II ,i I I i I I I I L......I.L..LL...L.11 g....

Kinetic Energy vs. Time2•• -•-i v i ! , , I v , i r r T-y-l--1T--r T- - r v I- v-

-' -- -

- 170(VN

US160•

:

EU

wsY 149 -

110

1 -

90 _- 1 t I m ! I f I I t , I , , ,L.IJJ.LLI .tlJ l t

0 50 199 159 200 259 300 19 400

Time (daysl

Figure 4.70 Experiment 8: Total kinetic energy per unitmass time series for 1984 over the entire domain (Units ofthe kinetic energy are cm2 9,2). Peak value of 215 cm2 s" 2 atday 1368 (yd 273).

131

Total Kinetic EnergyI I I

- - monthly 81

2001 monthly 82

monthly 83

i.... onthly 8.,

S15o-U)

S- -

EI I°

I00-- "| ... -

I50- ,

0!

0 250 500 750 1000 1250 1500Time (dav)

Figure 4.71 Experirent 8: Total kinetic energy per unitmass time series for 1981, 1982, 1983, and 1984 over theentire domain (Units of the kinetic energy are cm2 s' 2 ).

132

V. SUOUARY AND RZCOIEDATIONS

A. SUMMARY

The different experiment runs are summarized in Tables

4.2, 4.4, and 4.5. In all first year runs (see Table 4.2),

both a surface equatorward current and a poleward

undercurrent developed. There was also a poleward coastal

surface current present during the winter season. Upwelling

was a seasonal feature which, as expected, had the coolest

temperatures during a non-El Nifto year (1981) and warmest

temperatures during an El Nifto year (1983). Both meanders

and eddies were generated. The eddies were cold core,

cyclonic, and had a size around the Rossby radius of

dsformation (30 km). Along with an equatorward surface

current, both meanders and eddies remained at the end of

each year. Instability analyses revealed that both

barotropic and baLoclinic processes were important eddy

generation mechanisms. In all first year runs, no filaments

were observed.

The follow-on (second year) model runs are sunmarized in

Table 4.4. In general, a weak coastal poleward surface

current was evident during the winter season in the northern

region of the domain for all years (Climo II, 1982 and

1984). A meandering equatorward surface current, already

133

present, at the start of these experiments was maintained.

A poleward undercurrent was generated in all experiments.

The eddies, already present at the start of the experiments,

were both cold core, cyclonic, and warm core, anticyclonic

eddies in Climo II and 1982, while in 1984 there were only

cold core, cyclonic eddies. The size and offshore extent of

the eddies were consistent with the first experimental runs.

Seasonal upwelling occurred with minimum temperatures of

-120 C for Climo II and 1982, and of -100 C for 1984. The

year 1984 had the largest extent of cool upwelled water as

expected for a year with the strongest equatorward winds.

Filaments developed in all three experiments, but was most

pronounced (as expected) in 1984. The filaments had an

offshore extent between 200 and 350 km. Instability

analyses revealed that both barotropic and baroclinic

processes were involved in eddy generation.

The last two years of the extended (four year) runs are

summarized in Table 4.5. Listed here are Climo IV, 1983,

and 1984. Similar results are obtained: A poleward coastal

surface current, a surface equatorward current, a poleward

undercurrent, along with embedded meanders and eddies. Of

interest, upwelling occurs later in 1983 (at yd 150) than

for the other years (yd 60 to yd 90). Although the minimum

temperature is the same (11.00 C) for all years, 1984

experienced a larger area of cooler water (all along the

coast) than that of the El Niflo (1983) year. In all

134

experiments, there were both cold and warm core eddies.

Finally, filaments were observed during Climo IV and 1984,

but not during 1983.

Experiments 1 through 6 investigated the formation or

generation of features such as currents, meanders, eddies,

and filaments. In Experiments 7 and 8 a quasi-steady

equilibrium state for the CCS was reached and the features

observed to develop in previous years were maintained.

Figure 5.1 plots the mean, eddy, and total kinetic

energy per unit mass for Climo, 1981, and 1983 (Experiments

1 - 3) together. During these first generation years,

Figure 5.1a shows 1981 had the most total kinetic energy and

1983 (El Nifto year) the least. This also holds true for

both the mean and eddy kinetic energy per unit mass plots

(Figures 5.1b and 5.1c). The decrease in kinetic energy

(total and mean) during the last few days of 1983 is not an

error, but rather an adjustment for continuation with the

start of the 1984 kinetic energy plots.

Figure 5.2 plots the mean, eddy, and total kinetic

energy per unit mass for Climo II, 1982, and 1984

(Experiments 4 - 6) together (the second years of

generation). The largest values of total, mean, and eddy

kinetic energy were observed during 1984 (Figure 5.2a

through 5.2c). Climo II had the least total and eddy

kinetic energy (Figures 5.2a and 5.2c), but both Climo II

135

and 1982 had nearly identical low mean kinetk• energy

(Figure 5.2b).

In all experiments, the atmospheric pressure cycle and

subsequent movement of low and high pressure patterns

affected the wind orientation and strength over the model

domain. The surface current was observed to respond to the

prevailing wind direction. As the wind turned equatorward

and exerted stress on the water surface, Ekman transport

offshore resulted in the upwelling of cooler water along the

coast. Interannual variability was thus observed as

expected.

In conclusion, the experiments showed that, due to the

wind forcing, features such as currents, meanders, eddies

and filaments could be generated and maintained. These

results support the hypothesis that wind forcing is a very

important mechanism for the generation of many of the

observed features in the CCS.

B. COMPARISON WITH OBSERVATIONS DURING AN EL N10 YEAR

It has been shown that the model results qualitatively

agree with available observations of the CCS during non-El

Nifo years. For example, the simulated surface and

subsurface currents, along with eddies and filaments agree

in size and magnitude with available observations of the

CCS, as listed in Batteen r& al. (1989).

136

Here the focus is shifted to comparisons of observed and

model results during an El Nifto year. Qualitative results

from both of the El Niflo experiments (3 and 8) along with

some observations taken in the CCS during the 1983 El Nifio

are presented in Table 5.1. Because the model does not

include remote forcing, the oceanic teleconnection will not

be expressed in the model results. There is still good

agreement between the model and observations taken during

the 1983 El Nifuo within the model domain. In particular,

warmer sea surface temperatures along with onshore advection

are evident, especially during the first three months of the

year. Poleward surface flow (for example Figure 5.3) is

enhanced and the entire current system appears weaker than

in the other model years. Based on these results, it is

concluded that atmospheric forcing played a substantial role

in the anomalous conditions observed in the CCS during the

El Nifto of 1983.

C. NAVAL RELEVANCE

As the Navy focus has recently shifted from blue water

to the littoral, EBC models such as the one used here take

on an increased importance. Although this EBC model would

require a finer scale before it could be used to predict the

location of features of interest, it is a start in the right

direction.

137

Accurately predicting the location of meanders, eddies

and regions of upwelling becomes critical for the successful

use of mines, along with aviation, amphibious, and covert

swimmer operations. The meanders and eddies could impact

several aspects of mining (i.e., laying, known position, and

mine removal). Smaller amphibious craft could get swept off

course if caught up in a strong jet associated with a

meander. The cold upwelled water may be nutrient rich and

support a plankton bloom which could significantly reduce

visibility in the water. In addition, the colder water

adversely affects swimmer immersion times.

Fog often results in upwelling regions where warmer air

is present over the cooler upwelled water. The effect of

this fog is to reduce surface visibility, which could be a

plus (such as to provide cover for an amphibious landing) or

minus (such as when defending an area against covert

operations). This decreased visibility may also affect

aviation operations by requiring instrument flight rules

(IFR) vice visual flight rules (VFR). Finally, other

optical and infrared devices will be degraded by the

presence of increased moisture in the atmosphere (i.e.,

fog).

D. RECON MTDATIONS

Future studies should let the model run for multiple

years, to allow for spin-up. As seen in multiple year

138

kinetic energy per unit mass time series plots, it appears

that spin-up may take only three to four years, but this

needs to be confirmed. Additional studies should use daily

rather than monthly winds to examine the effects of events

and relaxations. The incorporation of bottom topography and

a more realistic coastline would allow preferred eddy

generation areas to be identified. The incorporation of

bottom topography could also lead to an even better

depiction of the undercurrent, which plays an important role

in eddy generation. Finally, finer horizontal and vertical

resolution should be incorporated into the model to aid in

more accurately predicting the location of meanders, eddies,

and filaments.

139

TABLE 5.1 COMPARISON OF OBSERVED AND MODEL RESULTS DURINGAN EL NINO YEAR (1983).

El Niuo (1983) observations Experiment 3 Experiment 8in CCS compared to mean (1983 cold (1983 extended

restart) run)

Warmer SST Simulated Simulated(1, 2, 3)

Weaker overall current Simulated Simulatedsystem(2)

Enhanced poleward flow Simulated Simulated(2, 3)

Enhanced onshore advection Simulated Simulated(1, 2, 3)

Maximum equatorward surface Simulated Simulatedcurrent farther offshore(2)

References: (1) Rienecker and Mooers (1986)(2) Simpson (1983)(3) Simpson (1984)

140

Total Kinetic Energy100- I

---- clino11.. 1monhly 81

0- ..... mo lly (cold) I / - "

- -I N "

U)6 0 - . - .

C.)E 4U .0 o/ *

20 "I""

-- / /

I /

/ .

/ I

20- . •

2 18

Time(day

Figre5.l Epermets1-3 Ttalkietc eery pr ni

oeurte entir doperient (Unit Tofthe kinetic energy arerul

cn2s"2)o

141

Mean Kinetic Energy100- I I I -

- morthly 81

80- monthly 83 (cold)

S60-

Em 40-

L\.

20-

. . . •

0- 1..0 60 120 180 240 300 360

Time (day)

Figure 5.1b Experiments 1-3: Mean kinetic energy per unitmass time series for climatology (1980-1989), 1981, and 1983over the entire domain (Units of the kinetic energy arecm2s -2).

142

Eddy Kinetic Energy100- t n

7 climo 81 1moithly 83 (cold)

80 _

.n 60-

</E

40- - --

/ .

20-0 6/ / 2

/ ./ / .;

/ / .

/7

. .. * . .- .

0 60 120 180 240 300 360Time (day)

Figure 5.1c Experiments 1-3: Eddy kinetic energy per unitmass time series for climatology (1980-1989), 1981, and 1983over the entire domain (Units of the kinetic energy arecm2 s- 2).

143

Total Kinetic Energy200- I I P

- - climo 2S- montily 82

• * • monthly 84 (icold)

150-."*•

S100- - -

50-

//

S- . * * --'•k /

*,

50-

0- 5 I 5 3 I I

300 360 420 480 540 600 660 720Time (dav)

Figure 5.2a Experiments 4-6: Total kinetic energy per unitmass time series for Climo II, 1981, and 1983 over theentire domain (Units of the kinetic energy are cm2 s' 2 ).

144

Mean Kinetic Energy200 n n n I

- climo 2

*.-.-.montlby 82

imonthly 84 (rcold)

150-

U)

E 100-0It'

v*

,.,, .. .. •.

0- I l I I I T T

300 360 420 480 540 600 660 720Time (dav)

Figure 5.21b Experiments 4-6: Mean kinetic energy per unitmass time series for Climo II, 1981, and 1983 over theentire domain (Units of the kinetic energy are cm2 s8 2 ).

145

Eddy Kinetic Energy200- I I

- - climo 2

*.... monthly 82

***moilthly 84 (rcold)

150-

iS , 6,

< 10

10 - ' "'- . . .

Iii

50 " -

300 360 420 480 540 600 660 720Time (dav)

Figure 5.2c Experiments 4-6: Eddy kinetic energy per unitmass time series for Climo II, 1981, and 1983 over theentire domain (Units of the kinetic energy are cm2 s' 2 ).

146

Distance off shore (kTi)

-1,24.0 -653.3 -662.7 -512.3 -341.3 -17f.7 3.3

14 60. - 1 AI I I I

0

1173.3- Li

0

93H. 7 -

A 704.1-In

.-. 14

S7@4 . 7 ---

In.

North-South vel contour at model day 45.0

Figure 5.3 Experiment 3: Surface meridional, component ofvelocity at day 45. The contour interval is 1 cm s-. Thedashed lines indicate equatorward velocities. Latitudinalalongshore distance 0 (1408) km corresponds to 350 N (47.50N). Note enhanced poleward flow.

147

APPUEDIX A. INSTABILITIES FOR ZXPERIMENT 1 (CLIMO)

This appendix contains additional analyses from

Experiment 1 (climatological year) for the periods when the

total kinetic energy per unit mass became quasi-steady.

Energy transfer plots which consist of barotropic (mean

kinetic energy to eddy kinetic energy) and baroclinic (eddy

potential energy to eddy kinetic energy) were produced for

the following model days: 207 - 216, 228 - 231, and 297 -

303. These plots appear as Figures A.1 through A.6.

149


-I 24.8 -853.3 -682.7 -512.A -341.3 -178.7 N.A

1171 3 -

93f8. 7 -

w1..

0"1:1• 704.P@- te. -

734.7-

Mean kinetic energy to eddy kinetic energy

avernge over model days 207.0 to 216.0

Figure A.1 Experiment 1: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) forclimatological (1980-1989) year, for model days 207 to 216.The contour interval is 1 ergs cm"3 8-1.

150


-1124.0 -5,31.3 -687.7 -512.0 -341.3 -178.7 0.8

140)" 8- - - L - -- I I I I V -TIM.", na.tt I 92

TIS.7-

"to

Tlfl. 7 -/ -

a)L |LU,.L

0

0 0

,41

"Fin."(

192.81

234.7 -

Eddy potential energy to eddy kinetic energyaverage over model days 207.0 to 216.0

Figure A.2 Experiment 1: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for climatological (1980-1989) year, for model days 207 to216. The contour interval is 1 ergs cm- 3 s"1.

151


-182A.8 -M53.1 -682.7 -5123. -341.3 -173.7 3.914Rnfl . - L - I I I I -

1173,. -

7AA. 7 -

0 J• 794 f.• -- "o

.' 469.3 -In

;,34.7 -

Menn kinetic energy to eddy kinetic energy

average over model days 228.0 to 231.0

Figure A.3 Experiment 1: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) forclimatological (1980-1989) year, for model days 228 to 231.The contour interval is 1 ergs cm" 3 a- .

152

D)istance off shore (kin)

-1124.0 -953., -682.7 -512.8 -341.3 -176.7 U.8

140n 0- I I II

l ife"ioIIIL'..

11 73.3 -

q3O. 7 - 1119.0

___ H ..,,

0"4 Me. 0 - °-

i~0

734.7--

ov~f

U hteII, .- , l°

r-a.7 - '-


Figure A.4 Experiment 1: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for climatological (1980-1989) year, for model days 228 to231. The contour interval is 1 ergo cm" 3 s81

153


-1•24.3 .853.3 -692.7 -512.3 -341.3 -170.7 N."

1409.0.- I I i I

1173.3-.

918.7--

I-. II ,.0

,d

4 469,.3---

234.7-

" .11- 1 1 1 1 IT - - -

Mean kinetic energy to eddy kinetic enerRy


Figure A.5 Experiment 1: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) forclimatological (1980-1989) year, for model days 297 to 303.The contour interval is 1 ergo 6m"3 s" 1

154

n ~~~~~~Ig t]I f II.neI I..

Distanc off shore (kin)

-1•24.3 -853,. -682.7 -512.3 -341.3 -17N.7 3.3,43fl *- I I I -

91nn7 tin,1" '

ll,".,j l.

00

.- 704.0--&n

00

234. 7 - -

0. p


Figure A.6 Experiment 1: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for climatological (1980-1989) year, for model days 297 to303. The contour interval is 1 ergs cm" 3 s".

155

APPEDIIX B. INSTABILITIES FOR EXPERIMEIT 2 (1981)


Experiment 2 (1981) for the periods when the total kinetic

energy per unit mass became quasi-steady. Energy transfer

plots which consist of barotropic (mean kinetic energy to

eddy kinetic energy) and baroclinic (eddy potential energy

to eddy kinetic energy) were produced for the following

model days: 210 - 222, 240 - 252, 297 - 303, and 309 - 333.

These plots appear as Figures B.l through B.8.

157


-1024.6 -853.3 -662.7 -512.0 -341.3 -176.7 0.0

1406 6 I I

1173.3-

11,m*,

930I. 7 -

I1• Ham.,

0. 74.-- 704 0-

0

IdU

234.7-

14,5..,

0.0- I I I I


average over model days 210.0 to 222,0

Figure B.1 Experiment 2: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1981,for model days 210 to 222. The contour interval is 10 ergscm 3 s-

158


-1024.0 -853.3 -682.7 -512.9 -341.3 -173.7 R.8

14"R.U- I I I

1173.3 H477.

31173.3 - L141.2 H,,,.4

11141.3LI41r,1A

0)

|,1.4.•

-0

746.3-

0te

CC

€15

--- 411,,.,

030

234.7 -lo

I'1II.S "

11,,... 411141.0

Figure 82 Experiment 2: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for 1981, for model days 210 to 222. The contour intervalis 10 ergs cm 3 s-.

159


--1924.0 -853.3 -682.7 -512.8 -341.3 -171.7 0. P

140988- I I I

an'r

1173.3-

18 .7-

SH..,

I-0 WIi.,.Q

0

- 3

..J 4 ,9.3- • -.

•734.7 - Lee.5

cm 8.

160*



Figure 3.3 Experiment 2: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1981,for model days 240 to 252. The contour interval is 10 ergs

-m3 -1

160


-124.3 -85•. 3 -682.7 -512.0 -341 .3 -173.7 3.31431.13- IL... I I I

1401 .0 -- 1 11 1".

l'161.3LIN.@3 11".

1173. 3-

93S. 7 -

• g76 7 4. 0J

SI|IIW~il |Wt

734.3-

04

ill.'llt~ •

U 0

234.7 7I


Figure B.4 Experiment 2: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for 1981, for model days 240 to 252. The contour intervalis 10 ergs cm- 3 s"1.

161

D~istance off shore (km)

-1824 0 -953.3 -682.7 -512.0 -341.3 -1 7 7 6.R

14• •. - I I J____ __

1173.3-

q•3.7- L3-

S..

0-~ 704.0-

6Ti

21 4.7- -1

m

7>34.7 -Ilwss

Mean kinetic energy to eddy kinetic energyaverage over model days 297.0 to 303.0

Figure B.5 Experiment 2: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1981,for model days 297 to 303. The contour interval is 10 ergscm 3 1

162


- 1024.1P -853.3 -682.7 -512. -341.3 -171.7 9.I140F1. 0 - -

1173.3-

938.7 -

0 .0 3 7040

&1I-o Ii.,,

0

C"

4j- 469.3--

4723.4 .7 --

0.0.tie.,,-

6.6-


Figure B.6 Experiment 2: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for 1981, for model days 297 to 303. The contour intervalis 10 ergs cm" 3 s"1.

163


-1924.0 -851.3 -682.7 -512.0 -341.3 -170.7 P.R, • .-I I I I -

1171.3-

9n 7F1

0

S469.3--

0


average over model days 309.0 to 33.1.0

Figure B.7 Experiment 2: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1981,for model days 309 to 333. The contour interval is 10 ergs

cm3 s-1

164

Distance off shore (km),124.9 -851.3 -682.7 -512.3 -341.3 -170.7 3.0

143113- 0 I ! I L _

1173.3-

131.7.

__

0)

7 74.0-

0

.' 469.3-

214f~. 7 --

Q0.7-

Illl, 14.

Eddy potential energy to eddy kinetic energyaverORe over model days 309.0 to 333.0

Figure S.8 Experiment 2: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for 1981, for model days 309 to 333. The contour intervalis 10 ergs cm3 s-.

165

APPENDIX C. INSTABILITIES FOR ZXPZRIMT 3 (1983)







model days: 186 - 192, 222 - 234, 249 - 258, 279 - 288, 312

- 315, 324 - 327, and 342 - 348. These plots appear as

Figures C.1 through C.14.

167


-1fl24.0 -895.3 -6132.7 -512.s -3W1.3 -173.7 3.3

1 Fin 63 -

1173.3-

q3S. 7 -

0"".

0

oo

O,

-~469.3-

234.7-

U..- I I 1 1 I


Figure C.l Experiment 3: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1983,for model days 186 to 192. The contour interval is 10 ergscm 3 -

168


-1•24.0 -353.3 -682.7 -512.9 -341.3 -17, 7 F."

14 09- - - l I I I I

1173.3-

fllsI.$

to°.. (i

"J t,.o~et',.o.

0. flls.@

J• 70 4 .0 - -

0

+ 469.3-

lltoofill""e,.g

-- II,,...

fIIl .4


Figure C.2 Experiment 3: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for 1983, for model days 186 to 192. The contour intervalis 10 ergs cm 3 s-1

169


-1824.8 -853.3 -692.7 -S12.1 -341.3 -170 7 0.6,490.8- I I I I I

MI,

1173.3-

938,7 -

L.

to

0 G

4' 469.1-

S• 7 -- l I',.. .

234.7-



Figure C.3 Experiment 3: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1983,for model days 222 to 234. The contour interval is 10 ergsC -3 9"I1

170


.1524.0 -853.3 -682.7 -512.6 -341 3 1711 7 1.4

1411 0 - _ -_ I -

~ ,, , tIe

lip 7

- tlat..

V Lowe a

0

S t",I. *U

7114 iP

0M

.aI IPMA• ,

Eddy potential energy to eddy kinetic energyaverage over model days 22.0 to 234 0

Figure CA4 Rxperitnent 3: Energy transfer@ of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for 1983, for weldays 222 to 234. The contour intervalis 10 erg. c"' @'I.

171


1,24 s -653 3 -66?.7 -S1?.6 -,"1 3 -179 7 66

1 400 a --- 11_ _-

4qa~ I

Mean kinti enrg to edd kieieeg

Now,

average ovrmdldy74. o28

S

a-3'

0-• 7t4 5-

0

S I I It .

cm

Mean kinetic energy to eddy kinetic energyaverage over model days 249.0 to 25860

Figure C.5 Experiment 3 : Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1983,for model days 249 to 258. The contour interval is 10 ergs

172


1U74 of -F191 6•9S .7 -512 6 -341.3 170 7 a.1140nl 4 - - I---- 1.. - I - -_ -

1171 1

tin w

'lIR 7

0

-2 704-

0

H,..

"Lam 794 M

00


Figure C.6 Experiment 3: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for 1983, for model days 249 to 259. The contour intervalis 10 ergs cm- 3 a--

173


-11924. -853.3 -682.7 -512.0 -341 .3 -171.7 9.!

1409."-

173. --

q9if. 7 -

L..

0

7 0

0'4".

)I4. 7 -

@.* - I-!-

Mean kinetic energy lo eddy kinetic energy


Figure C.7 Experiment 3: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1983,for model days 279 to 288. The contour interval is 10 ergsm-3 S-.

174


-1024.0 -853.3 -68..7 -512.0 -341.3 -170.7 0.0140111- I I I I

1404..0

114444

1173.3'--

II444.

1II,4 4

q3r1.7 -

0

II 114.44

0-l= 794.9f -'44,•

0

114444 11444

I1

0(5

2 .7- H44 H..0

•4 11441441


Figure C.8 Experiment 3: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for 1983, for model days 279 to 288. The contour intervalis 10 erg. cm"3 g"l.

175


-1824.,l -OC3,.3 -602.7 -512.g -341.3 -170,7 1.1

LIII.4?

173.3

-. ,i i 21 0* -

¶ 7 1 .

1 --

0 0

0*714.1K111.10 *0

+a 469 3 -. "Los-0 0-

o o.

*0



Figure C.9 Experiment 3: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1983,for model days 312 to 315. The contour interval is 1 ergocm-3 8-1.

176


-1024.0 -8•3.3 -602.7 -512.9 -341.3 -170.7 "l.al

14PS0 - I I I II I--V - _T _

fe*

NIL

r-->4 0 111

0

0.

387-

0 IT

". oe o d 30 t.

todd knt en in

for 1983, for model day. 312 to 315. The contour intervalis 1 erg. cm"3 u"I.

177


-1324.3 -8953.3 -682.7 -512.3 -341.3 -1711.7 3."

140B(1.0- I I I

910. 7 18.0

A 7(14.0-

o t

a C

469.3-

CDto..'

1. - I "



Figure C.11 Experiment 3: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1983,for model days 324 to 327. The contour interval is 1 ergsc-3 -1"

178


-1024.8 -053.3 -682.7 -512.6 -341.3 -17F.7 9.91 .-I I I I _ _

1173.3 --

0

0) 0

164, - L, 00

a .00*Hm etC7

oo

aver.,e ove moe as340t 2.

179m

,0

)vr3eoermde.oy7- 0to370

Figure C.12 Experiment 3: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for 1983, for model days 324 to 327. The contour intervalis 1 ergs cn" 3 S"1

179


-1824.0 -851.3 -682.7 -512.0 -341.3 -170.7 0.0

146R 8 i- _ I I I

1173.3-

|tW4,IS

93". 7-

C3

04 ll•7.4.0on

+a 469.3-

0

734 .7-'44.6. 7 -'*


Figure C.13 Experiment 3: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1983,for model days 342 to 348. The contour interval is 1 ergs

l-3 s-1"

180


-1024.0 -853.3 -6f02.7 -512.0 -341.3 -170.7 0.0

140R 0- - _ _ _ _ _ __ _

list

6.40

1173.3-

36. 7 --

0

o

WIV

14*35,

0i!.. e

FEddy potential energy to eddy kinetic energy


Figure C.14 Experiment 3: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for 1983, for model days 342 to 348. The contour intervalis 1 ergs cm" 3 s"1.

181

APPENDIX D. INSTABILITIES FOR ZXPERIENCT 4 (CLIKO I1)


Experiment 4 (Climo II) for the periods when the total

kinetic energy per unit mass became quasi-steady. Energy

transfer plots which consist of barotropic (mean kinetic

energy to eddy kinetic energy) and baroclinic (eddy

potential energy to eddy kinetic energy) were produced for

the following model days: 378 - 408 (yd 12 - 42), 453 - 465

(yd 87 - 99), 504 - 516 (yd 138 - 150), and 624 - 636 (yd

258 - 270). These plots appear as Figures D.1 through D.8.

183

D~istance off shore (kim)

1924 P P%3 :i 6V 7 512 a -3.1 3i Ila 7 a 6

11 71 1

q3n. 7 -

L.~~ ~ C9 - _•3.

tim. 6

6,• .

0 711 .R -.

to

0

469.3- fiwe s

0

P34. 7 - 'lg.HNCN


Figure D.1 Experiment 4: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for ClimoII, for model days 378 to 408 (yd 12 - 42). The contourinterval is 1 ergs cm" 3 s"1.

184

Distance off Shorf, (kin)

tWP4 a h1451 1 611 7 417 34J 1 3 11 7 I7 Ia

'3 -- - J -

"10o 71lot III

foli-

um

ti0

'I

40

LooWII

0 04

Eddy potential energy to eddy kinetic energy


Figure D.2 Experiment 4: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for Climo II, for model days 378 to 408 (yd 12 - 42). Thecontour interval is 1 ergs cm" 3 s0-.

185

iLptanee off shore (kin)

-61P . ! . . .. 7 -S I 1341 3 179 7 U.6

0~s---------L 1 L _ _ -L

9.11. 7 -q: i00

7194.7 -

0

+'469.3-

234.7 a-

I -. II • 1 -

Mean kinetic energy to eddy kinetic enrrgyaverage over model days 453.0 to 465 0

Figure D.3 Experiment 4: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for ClimoII, for model days 453 to 465 (yd 87 - 99). The contourinterval is 1 ergs cm" s3a.

186


-1I14. -893.3 -682.7 -517.8 -3AI .3 -17 W 7 1.1

14PO - L0 i 1 1. A- - -

Itng

'nft 7.'..' -- ma

_ •

0

1 79234.7--

-2

C,1

"i" '.

•'4 7 -- , U-

P. 11-O OLI


Figure D.4 Experiment 4: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for Climo II, for model days 453 to 465 (yd 87 - 99). Thecontour interval is I ergs cm"3 s81.

187

D)istance off shore (km)

-102a.8 -RIS .3 -682.7 -512, -341.3 -171. 7 3.9

14PO 0 - - I-L J LL_.!

11 7:.:; -

111. 7 -

0)

I.I

70.3R.- "• -

X3 ' 0.

0

- °

234.7- -

0.9 02


Figure D.5 Experiment 4: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for ClimoII, for model days 504 to 516 (yd 138 - 150). The contourinterval is 1 ergs cm"3 s"I.

188


-1024.0 -953.1 -682.7 -512.3 -341.3 -176.7 R.'

I 4f - - _ _ 11 I - 1-

1171. 3

S1. 7..1-" 9 /1n. 7 - 139, 116 -

A 784.0-

0

46q. 3 -

'is..,

'34 7--• 0 -

0 .,0

3..- tu.nli..


Figure D.6 Experiment 4: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for Climo II, for model days 504 to 516 (yd 138 - 150). Thecontour interval is 1 ergs cm" s- .

189


-1824.01 -815.3 -692.7 -512.0 -341.3 -1 73.7 3.3

140 - I Ia

0U

1173.3-

469. 7 -

°

l112

tin.,

It.,.. I,.,..

21•4.7 - ,

7-M.

Mean kinetic energy to eddy kinetic energynvernge over model days 624.0 to 636.0

Figure D.7 Experiment 4: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for ClimoII, for model days 624 to 636 (yd 258 - 270). The contourinterval is 1 ergs cm"3 a"1.

190

Distance off shore (kin)-1024.3 -953.3 -692.7 -512.1 -341.3 -178.7 8.9

14P1n. ... J I I I I

* IILI Hi

1173.3- Irk.

0

q36.7 - a

A .P I __

0

7fl4 .-- •flu."-

• -' 421 .7 -

C,>


Figure D.8 Experiment 4: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for Climo II, for model days 624 to 636 (yd 258 -270). Thecontour interval is 1 ergo cm 3 s-.

191

APPZNDIX Z. INSTABILITIES OR EXPZRIMMIT 5 (1982)







model days: 507 - 516 (yd 141 - 150), and 525 - 528 (yd 159

- 162). These plots appear as Figures E.1 through E.4.

193


-10124.0 -953.3 -682.7 -512.1 -341 .3 -170.7 N.91409~ 0- !I ___I__

I,,4*

1173.3 -j4.w

93fl. 7 -

00U,4

70 .0 1154." 0

00

C) 0

469.3- 344. 0

• 734. 7

6

a a

,,- . I 4. I-- .

Vo


Figure 3.1 Experiment 5: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1982,for model days 507 to 516 (yd 141 - 150). The contourinterval is 1 ergs cm"3 8" .

194


-11824.8 -853.3 -68,2.7 -512.I a -341.3 -170.7 7.8,140,8- I . I I I___I

1136.83

117.1 - q

938.7-

0 if-

I.. 'K

0In

to

0"

S469.3 -1353_

2_34.7 --

0 .

0.0- tI

Eddy potential energy to eddy kinetic energyaverage over mudel days 507.0 to 516.0

Figure 3.2 Experiment 5: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for 1982, for model days 507 to 516 (yd 141 - 150). Thecontour interval is 1 ergs cm- 3 s"-.

195


[email protected] -953.3 -682.7 -512.0 -341.3 -173.7 P.0

140.0-1 I 1

I'.,,

1173.3-

93n. 7 -

0 •

I1.0

0

0

-• ,169.3-

z)0



Figure R.3 Experiment 5: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1982,for model days 525 to 528 (yd 159 - 162). The contourinterval is 1 ergs cm"3 a"1.

196

9.3- I I

Distance off shore (km)-11N24. -953.3 -682.7 -512.1 -341.3 -176.7 01.6

1410.1- I I ! I

1173.3-

9383.7-

0 .V

14U, " - ,?"''-

0 ,-- . V 0" - .t°. , 6 "*

""0

0 I,, 46g.3- ::J J i ! - " -'.

m•_

214.7-

o~V.

evernge over model days 525.0 to 526.0

Figure 3.4 Experiment 5: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for 1982, for model days 525 to 528 (yd 159 - 162). Thecontour interval is 1 ergs cm-3 s-.

197

APPENDIX F. INSTABILITIES FOR ZXPERIMENT 6 (1984)






tc eddy kinetic energy) were produced for the following

model days: 576 - 591 (yd 210 - 225), 606 - 624 (yd 240 -

258), and 645 - 657 (yd 279 - 291). These plots appear as

Figures F.1 through F.6.

199


-1•24.9 -953.3 -682.7 -S12.9 -341.3 -17N.7 N.@

14011.9-

1173.3-

q3R .7 -

'.X

0

934

Mean kinetic energy to eddy kinetic energyaverage over mnodel days 576.0 to 591 0

Figure 1.1 Experiment 6: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1984,for model days 576 to 591 (yd 210 - 225). The contourinterval is 10 ergs cm 3 *r.

200


.,324.9 -853.31 -682.7 -512.3 -341.3 -170.7 I.'- I,..L.-I_____I-

HI.....

117,.3-

q3R.7 -

4)

LI .

0

-0 704 . 7 -

V}

,- 0

I M - II I

Eddy potential energy to eddy klnetic energ~yaverage over model deys 578.0 to 591.0

Figure F.2 Experiment 6: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for 1984, for model days 576 to 591 (yd 210 - 225). Thecontour interval is 10 ergs cm"3 s"1.

201


-124.1 -653.3 -682.7 -512.1 -341.3 -176.7 S.PIAPn's- I

.173. 3 - 144

936.7 -7

0)

• : 794.0-

bo0

- 4'd11M.4 14

469.3-

fl V

IN4., lsN., '0

23 . -1

,jA

Tim., •.

0.8- I I


Figure F.3 Experiment 6: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1984,for model days 606 to 624 (yd 240 - 258). The contourinterval is 10 ergs cm"3 S&r.

202


-1•124.1 -9.53.3 -682.7 -S12.. -341 .3 -171.7 0.0

1468.8- I I I___1_1 -

11165.1 1-104.7 Inell .1 1ý9'.I

ll1M.8

1173.3-

'11Wtm [1a

91FIS 7 -

If,,

~llma

09 741.04-

0- I

IM

0.9

Edd pnl-4 .

203

'1rn.a .


Figure P.4 Experiment 6: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for 1984, for model days 606 to 624 (yd 240 - 258). Thecontour interval is 10 erg. c- 3 s-1.

203

Distance off shore (kin)-1824.9 -853.3 -682.7 -512.3 -341.3 -173.7 .6

t148.t

1173.3-

93. 7-

0)

0

[1...,

N• 469•,.3 -

234.7 -

Mean kinetic energy to eddy kinetic energyavernge over model days 645.0 to 657.0

Figure F.5 Experiment 6: Energy transfers of mean to eddykinetic energy (i.e., barotropic energy transfer) for 1984,for model days 645 to 657 (yd 279 - 291). The contourinterval is 10 ergs cm"3 2r.

204


-1324.9 -153.3 -682.7 -512.3 -341.3 -173.7 3.9•4 9. .9 I I I I

I ! 7.!. 31-325 .

1173.3-

93"1. 7 -

0

A 704.0- _., -

°0m}• " 0

00

,14.7--0


Figure F.6 Experiment 6: Energy transfers of eddy potentialto eddy kinetic energy (i.e., baroclinic energy transfer)for 1984, for model days 645 to 657 (yd 279 - 291). Thecontour interval is 10 ergs cm"3 8"1.

205

LIST OF RuFUR.UCIS

Allen, J.S., 1980: Models of wind-driven currents on thecontinental shelf. Ann. Rev. Fluid Mech., 12, 389-433.

Arakawa, A., and V.R. Lamb, 1977: Computational design ofthe basic dynamical processes of the UCLA generalcirculation model. In, Methods in Computational Physics,J. Chang, ed., Academic Press, 17, 173-265.

Batteen, M.L., 1989: Model simulations of a coastal jet andundercurrent in the presence of eddies and jets in theCalifornia Current System. In, Poleward Flows AlongEastern Ocean Boundaries, S.J. Neshyba, C.N.K. Mooers,R.L. Smith and R.T. Barber, eds., Springer-Verlag, 263-279.

Batteen, M.L., and Y.-J. Han, 1981: On the computationalnoise of finite-difference schemes used in ocean models.Tellus, 33, 387-396.

Batteen, M.L., R.L. Haney, T.A. Tielking, and P.G. Renaud,1989: A numerical study of wind forcing of eddies andjets in the California Current System. J. Mar. Res., 47,493-523.

Batteen, M.L., M.J. Rutherford, and E.J. Bayler, 1992: Anumerical study of wind- and thermal-forcing effects onthe ocean circulation off Western Australia. J. Phys.Oceanogr., 22, 1406-1433.

Bjerknes, J., 1966: A possible response of the atmosphericHadley circulation to equatorial anomalies of oceantemperature. Tellus, 18, 820-829.

Blumberg, A.F., and G.L. Mellor, 1987: A description of athree-dimensional coastal ocean circulation model. In,Three-dimensional Ocean Models, N. Heaps, ed., AmericanGeophysical Union, 4, 1-16.

Breaker, L.C., and C.N.K. Mooers, 1986: Oceanic variabilityoff the central California coast. Prog. in Oceanogr.,17, 61-135.

Camerlengo, A.L., and J.J. O'Brien, 1980: Open boundaryconditions in rotating fluids. J. Comput. Physics, 35,12-35.

207

Carton, J.A., 1984: Coastal circulation caused by anisolated storm. J. Phys. Oceanogr., 14, 114-124.

Carton, J.A., and S.G.H. Philander, 1984. Coastal upwellingviewed as a stochastic phenomena. J. Phys. Oceanogr.,14, 1499-1509.

Chelton, D.B., 1984: Seasonal variability of alongshoregeostrophic velocity off central California. J. Geophys.Res., 89, 3473-3486.

Enfield, D.B., 1989: El Nifto, past and present. Rev.Geophys., 27, 159-187.

Haines, R.T., 1994: A numerical study of interannual windforcing effects on the California Current System, 1980-1983. M.S. Thesis, Naval Postgraduate School, 138 pp.

Halliwell, Jr., G.R., and J.S. Allen, 1987: The large-scalecoastal wind field along the west coast of NorthAmerica, 1981-1982. LT. Geophys. Res., 92, 1861-1884.

Han, Y.-J., 1975: Numerical simulation of mesoscale eddies.PH.D. Thesis, University of California, Los Angeles, 154pp.

Haney, R.L., 1974: A numerical study of the response of anidealized ocean to large-scale surface heat and momentumflux. &7. Phys. Oceanogr., 4, 145-167.

Haney, R.L., 1985: Midlatitude sea surface temperatureanomalies: A numerical hindcast. J7. Phys. Oceanogr., 15,787-799.

Hickey, B.M., 1979: The California Current System -hypothesis and facts. Prog. Oceanogr., 8, 191-279.

Holland, W.R., 1978: the role of mesoscale eddies in thegeneral circulation of the ocean - numerical experimentsusing a wind-driven quasigeostrophic model. &7. Phys.Oceanogr., 8, 363-392.

Holland, W.R., and M.L. Batteen, 1986: The parameterizationof subgrid scale heat diffusion in eddy-resolved oceancirculation models. 7. Phys. Oceanogr., 16, 200-206.

Huyer, A., 1983: Coastal upwelling in the California CurrentSystem. Prog. in Oceanogr., 12, 259-284.

208

Huyer, A., P.M. Kosro, S.J. Lentz, and R.C. Beardsley, 1989:Poleward flow in the California Current System. In,Poleward Flows Along Eastern Ocean Boundaries, S.J.Neshyba, C.N.K. Mooers, R.L. Smith and R.T. Barber,eds., Lecture Notes on Coastal and Estuarine Studies,Springer-Verlag, 142-159.

McCreary, J.P., P.K. Kundu, and S.-Y. Chao, 1987: On thedynamics of the California Current System. J. Mar. Fles.,45, 1-32.

Mitchell, R.P., 1993: A numerical study of seasonal windforcing effects on the California Current System. M.S.Thesis, Naval Postgraduate School, 125 pp.

Mooers, C.N.K., and A.R. Robinson, 1984: Turbulent jets andeddies in the California Current and inferred cross-shore transports. Science, 223, 51-53.

Nelson, C.S., 1977: Wind stress and wind stress curl overthe California Current. NOAA Tech. Rep. MaffS SSFR-714,U.S. Dept. Commerce, 87 pp.

O'Brien, J.J., R.M. Clancy, A.J. Clarke, M. Crepon, R.Elsbery, T. Ganuelsrod, M. MacVean, L.P. Roed, and J.D.Tompson, 1977: Upwelling in the ocean: Two- and Three-dimensional model of upper ocean dynamics andvariability. In, Modelling and Prediction of the UpperLayers of the Ocean, E.B. Kraus, ed., Pergamon Press,New York, 178-228.

Pedlosky, J., 1974: Longshore currents, upwelling and bottomtopography. J. Phys. Oceanogr., 4, 214-226.

Philander, S.G.H., 1990: El Nifio, La Nifla, and the SouthernOscillation. Academic Press, Inc., 289 pp.

Philander, S.G.H., and J.-H. Yoon, 1982: Eastern boundarycurrents and coastal upwelling. J. Phys. Oceanogr., 12,862-879.

Rienecker, M.M., and C.N.K. Mooers, 1986: The 1982-1983 ElNifto signal off northern California. J. Geophys. Res.,91, 6597-6608.

Semtner, A.J., and Y. Mintz, 1977: Numerical simulation ofthe Gulf Stream and midocean eddies. J. Phys. Oceanogr.,7, 208-230.

209

Simpson, J.J., 1983: Large-scale thermal anomalies in theCalifornia Current during the 1982-1983 EH Niflo.Geophys. Res. Lett., 10, 937-940.

Simpson, J.J., 1984: El Nifo-induced onshore transport inthe California Current during 1982-1983. Geophys. Res.Lett., 11, 233-236.

Tielking, T.A., 1988: Wind forcing of eddies and jets in theCalifornia Current System. M.S. Thesis, NavalPostgraduate School, 107 pp.

Tisch, T.D., S.R. Ramp, and C.A. Collins, 1992: Observationsof the geostrophic current and water masscharacteristics off Point Sur, California, from May 1988through November 1989. J. Geophys. Res., 97, 12535-12555.

Trenberth, K.E., W.G. Large, and J.G. Olson, 1990: The meanannual cycle in global ocean wind stress. J. Phys.Oceanogr., 20, 1742-1760.

Weatherly, G.L., 1972: A study of the bottom boundary layerof the Florida Current. J. Phys. Oceanogr., 2, 54-72.

Wickham, J.B., A.A. Bird, and C.N.K. Mooers, 1987: Mean andvariable flow over the central California continentalMargin, 1978-1980. Cont. Shelf Res., 7, 827-849.

210

INITIAL DISTRIBUTION LIST

No. Copies

1. Defense Technical Information Center 2Cameron StationAlexandria, VA 22304-6145

2. Librarian, Code 52 2Naval Postgraduate SchoolMonterey, CA 93943-5101

3. Chairman (Code OC/Bf) 1Department of OceanographyNaval Postgraduate SchoolMonterey, CA 93943-5122

4. Chairman (Code MR/Hy) 1Department of MeteorologyNaval Postgraduate SchoolMonterey, CA 93943-5114

5. Dr. Mary L. Batteen, (Code OC/Bv) 2Department of OceanographyNaval Postgraduate SchoolMonterey, CA 93943-5122

6. Dr. Curtis A. Collins, (Code OC/Co) 1Department of OceanographyNaval Postgraduate SchoolMonterey, CA 93943-5122

7. Dr. Leslie K. Rosenfeld (Code OC/Ro) 1Department of OceanographyNaval Postgraduate SchoolMonterey, CA 93943-5122

S. LT James Vann 212 Hedgerow PlaceJackson, TN 38305

9. Director, Naval Oceanography Division 1Naval Observatory34th and Massachusetts Ave, NWWashington, DC 20390

211

10. Conmander 1Naval Meteorology and Oceanography Command1020 Balch BoulevardStennis Space Center, MS 39529-5005

11. Commanding Officer 1Naval Oceanographic OfficeStennis Space Center, MS 39529-5000

12. Commanding OfficerFleet Numerical Meteorology and Oceanography Center 17 Grace Hopper Avenue, STOP 1Monterey, CA 93943-5001

212

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