UNITED STATES DEPARTMENT OF T

GEOLOGICAL SURVEY

COLLEGE OBSERVATORY FAIRBANKS, ALASKA

HE

ATA

OPEN FILE REPORT

INTERIOR

- MAY 198u 11

ORDER OF CONTENTS

Explanation of Data & Reports

Magnetic Activity Report

Outstanding Vagnetic Effects

Principal Magnetic Storms

Preliminary Calibration Data & Monthly Mean Absolute Values

Magnetogram Hourly Scalings

Sample Format for Normal & Storm Magnetograms

Normal Magnetograms

Storm Magnetograms (When Normal is too disturbed to read)

T H I S REPORT WAS PREPARED UNDER THE DIRECTION OF JOHN B , TOWNSHEND, CHIEF OF THE COLLEGE OBSERVATORY WITH THE ASSISTANCE OF OBSERVATORY STAFF MEMBERS J , E n PAPP, E,A. SAUTER, AND S , P , TILTON, AND I N COOPERATION WITH THE GEOPHYSICAL INSTITUTE OF THE UNIVERSITY OF ALASKA, THE COLLEGE OBSERVATORY I S A PART OF THE BRANCH OF ELECTROMAGNETISM AND GEOMAGNETISM OF THE U.S, GEOLOGICAL SURVEY,

COLLEGE OBSERVATORY PRELIMINARY ,SEOMaGNETIC DATA

INTRODUCTION OBSERVATORY LOCATION

The preliminary geomagnetic data included here is made available to scientific personnel and organizations, as part of a cooperative effort and on a data exchange basis because of the early need by some users. To avoid delay, all of the data is copied from original forms processed st the observatory: therefore it shouid be regarded as preliminary. Inquiries about this report or about the College Observatory should be addressed to:

Chief, College Observatory U .S. Geological Survey 'i~kon Drive on West Ridge Fairbanks, Alaska 99701

Requests for copies of the magnetogrm.~ except for the currenz month should be addressed xo:

bbrld Cata Center A-NOAA fivirormental Data Service aoulder, Colorado 803C2

GEOMAGNETIC DA'I'A

Normal, Storm, and Rapid Run magnetograms and appropriate calibration data are processed daily at the observatory and are available for analysis or copying. Also avaiiable are mean hourly scalings, K-Indices, selected magnetic phenomena reports, and on a real-time basis are recordings from a 3-compo- nent fluxgate magnetometer and F-component proton magnetometer.

blagnetic Activitj. The K-Index. The K-Index is a logarithmic measure-

ment or' the r u e of the most disturbed component (D or H) of the geomabetic field for eight inter;als beginning 0000-0900, 0300-0600.. ,2100-2400 UT. It is a measure of the difference between the hignest and lowest deviation from a smoozh curve ;o be expected for a component on a mgnetically quiet day, within a three hour interwi.

The Equivalent Daily Amplitude, AK. The K-Index is conver'ed into an equivalent range, ak, .~tich is near the center of the limiti-ng g m a ranges for a given K. The average of the eight values is called equivalent aailg amplitude AK. The unit l0yhas been chosen so as r.otto give the illusion of an accuracy not justified.

The scheaule for converting gamma range to K, and d to ak is as follows:

Gama Range K - Index - ak* 0 < 25 0 0

The Magnetic Daily Character Figure, C. To each Universal day a character is assigned on the basis C=O, if it is quiet; C=l if it is moderately disturbed; C=2 if it is greatly disturbed. The method used to assign characters at the College Observatory is based on AK as follows:

AK Range C 3 3 11 a 11s 50 1 50+ 2

Routine assignment of C was discontinued at College on January 1, 1976.

The College Observatory, operated by the U. S. Geological Survey, is located at the University of Alaska, Fairbanks, Alaska. It is near the Auroral Zone and the northern limit of the world's greatest earthquake belt, the circum-Pacific Seismic belt. Although the 0bse~atory's basic operation is in geo- magnetism and seismology, it cooperates with other scientists and organizations in areas where the facil- i.ty and personnel can be 3f servtce.

The observatory is one of three operated by the USGS in Alaska. The others are located at Barrow and Sitka.

The position of the observatory site is: Geographic latitilde. . . . . . . .64'51.6' N Geographic longitude.. . . . . .117°50.2'~ Geomagnetic latitude. . . . . . . +64.6' Geomagnetic longitude . . . . . . c256.5' Elevation .................. 200 meters

Selected P3enonena & Outstanding ?&metic Effects Prior to Januarv 1. i976, the Normal & .b~id

Run records were reviewed at the observatory for seleczed magnetic phenomena and the events identified were forwarded to the IUGG Commission on Magnetic TJariations and Disturbances. This was discontinued on January 1, 1976, but s report on Outstanding Xagnetic Sffects is prepared monthly for this report.

Principal bgnetic Storms Gradual and sudden commencement magnetic distur-

bances with at least one K-Index of 5 or greater, which are believed to be part of a wrld-wide disturbance, are classified as principal magnetic storms. The time of the storm beginning and ending; direction and amplitude of sudden commencements; period of maximum activity; acd storm range are reported. %onthly reports of these data are forsarded to the World Data Censer A in Boulder, Colorado.

Magnetogram Hourly Sczlicgs Magnetogram b~uriy scalires are averages for

successive pericds of one hour for the D, H, and 2 elements. The value in The c o l m hesded "01" is the average for the hour beginning 0000 and ending 0100. Note that the values on the scaling sheets are in ter~ths of m with the decinal point omitted. The user of these scalings should keep in mind that the zabular values are hourly means and if he is interested in the detailed morphology of the magnetic field, he should refer directly to xhe magnetograms.

Magnetograms The normal maenetoerams in :his report are reprq- - -

duced at about one-third the size of the originals; Pre- liminary base-line values and scale values adopted for use with the original ,mgnetograms are included. For days when the nagnetic field is -33 disturbed for the Norpal magnetogram to be realable,Stom "agnetograms are repro- duced.

Absolutes, Base-lines, and Scale 7alues To determine ?he absolute value sf the magnetic

field from the hourly means or from point scalings the foilowing equaticns should be ilsed:

D=BD-d.S~; H=%$+h.Sy; YO=BZ+z'SZ where D, H, and Z ai.e absolute values; 3 ~ , 9~ and BZare base-line values; SD, SH and Sz are scale values; and d, h, and z are scalings ir. millimeters.

U. 5. DEPARTMENT OF COMMERCE NUAA FORM 76-133 NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION (9-72)

MAGNETIC AC'TIVITY (Greenrich civi l time, counted from midnight to midnight)

OBSERVATORY

COLLEGE, ALASKA

MONTH AND YEAR

WY

AK - o 5 02 01 02 03

16 06 07 23 06

2 3 24 10 21 06

03 00 02 14 04

01 04 12 2 5 34

06 03 03 04 07 24

SUM

11 0 5 02 05 08

2 2 1 3 1 3 28 12

28 29 16 2 5 11

07 00 04 19 1 0

02 09 16 26 31

13 08 06 09 15 29

K-INDICES

* 9 S Z y 5 5 9 ; ;

1 2 1 0 0 0 0 0 0 0 0 0 2 1 0 0 2 2 1 2

4 3 1 1 2 2 2 2 1 1 1 1 4 5 3 3 1 1 2 1

3 4 4 4 4 3 3 2 0 1 3 4 2 3 4 2 2 0 1 0

1 0 0 0 0 0 0 0 0 1 0 0 5 4 2 2 1 1 0 0

0 0 0 1 2 2 0 0 5 4 1 1 4 5 5 3 5 5 2 2

1 0 1 2 0 0 1 0 0 2 0 0 1 1 3 1 1 2 2 2 4 5 2 4

1

2

3

4 5

6

7

8 9

1 0

1 1

12

13

14

IS

16

17 18

19

20

21

22

23

24

2 5

26

27

28

2 9

3 o 31

(mm)

(Y/mm)

3 2 0 2 2 1 1 1 0 1 1 0 0 2 0 0 0 0 1 0

3 2 4 4 1 1 2 1 2 3 3 1 4 2 3 4 3 1 2 1

2 2 4 5 5 4 4 4 2 3 2 1 5 5 2 2 1 3 3 1

1 2 2 1 0 0 0 0 0 0 0 3 0 1 2 3 2 2 2 2

0 0 1 0 1 2 1 1 2 2 1 0 1 1 2 5 3 3 5 6

3 2 2 2 2 2 2 1 2 1 1 0 0 1 1 1 2 2 3 1 3 4 3 4

1980

TIME SCALE ON MAGNETOGRAMS

20 m m h

SUDDEN COMMENCEMENTS

d h rn

POSSIBLE SOLAR-FLARE EFFECTS BASED ON

INSPECTION O F GRAMS ALONE (WITHOUT

REFERENCE T O D A T A FROM OTHER SOURCES)

z

B E G I N

d 11 m

LOWER LIMIT FOR K = 9 . . . . a ..-

H

321.7 7.81

K S C A L E USED:

LOWER LIMIT FOR K = 9. .... . ... CURRENT SCALE VALUE... .. ...

E N D

d h m

D

683.8 3.75

( t o n e a r e s t lo?') 2560

S C A L I N GS AND COMPUTATIONS HAVE BEEN CHECKED.

JOHN B. TOWNSHEND, CHIEF, COLLEGE OBSERVATORY O B S E R V E R I N C H A R G E

N O A A F O R M 76-183 S U P E R S E D E S C b G S F O R M 8 1 1 * U.S. G O V E R N M E N T P R I N T I N G O F F I C E : 1978-761-817

2510

I COIJSE OBSERVAIPORY, CO-I AIASICA -- PRELDURART C-W DATA POW: M A Y /980 1

I I I I I I s m MAGHEMC-

PWIm CALZBRATIcm CCMKmERT -

ma4 I TO scm VALIJE BASE=

oooo u.~, 5-/- 3400 OX, 5-3)-80 Z /S/m/n 29.7 X/W 23" 4'6'. k E

D

- -

OW 0.T. 5-/-80 2q00 19. T, 5-3/- 80 94.0 v.h?7 //523 if I

RAPID Hlm MAC=-

CALIBRATIrn

SCAIE VAUIE c-m

D

mum FRa4 TO

. . . . - .- - . - -. - -- ~.. - -- N O A A F O a H 76-lo& 11-121 N I T l O N I L O C E l N l C A N 0 &TMOSPHERIC AOMINISTFATION

MAGNETOGRAM HOURLY SCALINCS ( U N I V E R S A L T I M E )

Vnluc- n r r i n t e n t h s 01 mm. and nrc c.vcrares lor s u r c c c s i v c per iods of "nc hmlr hcrinninL at midnigh,, l lour 01 lncnl day ( ~ ~ L I . T . ) i s hour& or rhc ~ m ~ u n i v r r s n l Jay.

SCALED Preliminary b o l e - l i n t ond stela vo1v.s:

I ~ I C I V S I Rssc- l ine Scelc CHECKED Be&innin& V a l u e V a l u e

( ) l n t r r p o l n t r d L ] s c n l l n r u o r r r r l i n t,rcnu,c M O N T H L Y SUM

n l mallnctlc "corm. 1-1 Signifxcanr port inn 01

Ihoor i n t c r p o l ~ ! e d . <> R c c n t d 011 s h e e t lor pnrt or 111 ol hour. 11 rn luc 8 ,

0 No rccord: or no values D l T E S W I T H G A P S :

n v a i l a h l c becaurc 01 i v c n , rurvc:.s e w i m t e d

faul ty rccord. For r n ~ r . ~ n ~ p r r t .

P U W C H E D D c f ~ v e d f r o m Storm ~ g ~ h . , c o n v c r t r d t o Normml ~ ~ p h . B Y

g u.5 G . P . O . 1913-769.511/932 R E G . I 6

0 -- 0

l l

! L 1:

- 'I

i; Z it -

.< . ;. g : . C I

' W .i - t: t ;a .t a !: 5

- i o

: 0 5 : J -d

2 z - - I -

- _ - v - m s - 4

g z % 5 " - -r ; 4 ; N 2 - . - > W I 2 ?I .? K + = z s;:: I";;

- sf.?; : K z Z " ,o 2 . l .S - I- 8 " ", ..n O

3 "Z '

4 C E - =i :.$

, I 0 . 6 4; 0 - '3.8

L, E " * .L n m u - ., 3 u - :$ 8 = u '.? - 5 ; * u $2 : z . :; - -- !!$ 2 i f -

D

$ E : - L O w - n c 5 .e c - 5,:

' .5 f - U b

;g - .e 0

22 +

:&

f c - - Y ,. c? - ., U

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