1992 CEDAR WorkshopBoulder, CO
June 21-26, 1992
Tutorial Lecture
by Raymond RobleNational Center for Atmospheric
Research
Overview of theThermosphere/lonosphere General
Circulation Model (TIGCM)
I
NCARTHERMOSPHERE/ieNBSFHEKE
GENERAL CIRCULATION MODEL(TICCM)
Primitive equations of dynamic meteorology adaptedto thermospheric heights
• Horizontal grid 5° latitude x 5° longitude, geographic
• Vertical grid —25 constant pressure surfaces, 2 gridpoints per scale height, 95 to 500 km
• Time step 240 or 300 S
INPUT
• Solar EUV and UV radiation 5 to 250 nm
• Empirical ionospheric convection and auroral particleprecipitation models
LONG RANGE MODEL DEVELOPMENT
1980
1989
MaZS1991
IonosphereDynamoMSIS
Aurora
Solar
Tides
DynamoAurora
Solar
Tides
Aurora
Solar
Tides
199^ Aurora (GEM^ Solar(R]>E)
199C Aurora (GEMJSolar (RISE)
TGCM
(100-500KM)
TIOCM
(•95-5(K)KM
TIE-GCM
('Qo-S'OO)
Atmobphcre Exi)l()r(TDynamics ExplorerRadar and Airglow
Atmosphere C\i»lorerDynamics Exph)r«TAir Force
CEDAJl
Atmosphere Exi)lor('rDynamic> Exi)l(>r< rSan Marco^
CED.\R
GEM
TIME-GCM
(30-oO()KM) ISTP
CEDAH
GEM
Air I orcc
CCM/TIME-GCM(0-500IvM)
U\RS
EOS
Global ChangeTimed
THERMODYNAMIC EQUATION p_ (3Pv "C
dT _ ge' ±_ .at PqC, dz
Kj. dT ^ PPr
+1 arlH dz
Molecular thermalconduction
- V •VT - WdT RTdz Cp m
horizontaladvection
vertical advectionand adiabaticexpansion
Iipppr Rnnndarv Conditions
No heat source or heat
sink at upper boundary
dT
dz= 0
Eddy thermalconduction
+(Q-L)
heat sources andradiative losses
TiOwer Boundary ConditionsTemperature specified r = r, (2 = - 7)
1
THE EASTWARD MOMENTUM EQUATION
du _ gg ^ ddt "" Pq dz
fL duH dz
+ / + — tan (^ - XxyV
-X u - V•Vu - w4^ T —I- (^X + Ky ^A„ u V VU
THE NORTHWARD MOMENTUM EQUATIONy \
du ^ je' d ^ _ / 4- Ji tan - X„ u-^-T7 l/_ 1
-x,y" -V-V.; li - 7
THE CONTINUITY EQUATION
1 +e^ 4-(«-'«')rcos 4> d<t> + rcos ^ dX 5z
THE HYDROSTATIC EQUATION
a<j> RT
Jpper Boundary Conditions
No sources of momemtuni
at upper boundary
imKCT Boiinflarv Conditions
Specified U — U,(zV = v,(z
(z
dz m
du _ ^ _ 0dz dz dz
a
= 0
T 400 km
MagneticField Line
ThermosphericWind
I
IONOSPHERE
J- 2(X)km
400 km
J- 200 km
Ions and electronsspiral up
IONOSPHERE
Ions and electronsdown
High atmospheric densityresults in increased electron-ion chemical recombination
LoMtf atmospheric densityresults in decreosedelectron-ion chemicalrecombination
ThermosphericWind
ION DRAG PARAMETERS
= Xj (1 - sin^ S cos- I)
Xyy = Xi (1 - cos^ Scos^ /)
Xjpy = + Xj sin Scos Scos^ / + Xg sin I
Xyj = + X^ sin Scos 6 cos- / + Xg sin I
where 6 is the magnetic declination angle, 1 is the magnetic dip angle and
(TpB' ChB-\ = — Xo = —
where Gp and (Tjj are the Pedersen and Hall electrical conductivity, respectively. B is thestrength of the magnetic field = 0.282 y 1 + 3 • COS" <j>^ Gauss, <j>i^ is the magnetic colati-tude, and p is the TGCM density.
JOULE HEATING
The Joule heating for displaced poles is
Qj = f + x„ (y,-y„ f + - x -u„)(v,-y„)
where and V,- are the geographic zonal and meridional ion drift velocities defined by theHeelis c< al (1982) empirical model and and are the zonal and meridional neutralwind components determined at a given time step in the TGCM.
^mPi^iCAL e^^TecM VGt^tTi
S^UiHC^ ^ ISO
ddcKM
y
r^
l^tO Km
LOCAL
LA
TIT
UO
e(0
«g
.)
S»
¥S
5^
S
iiiiM
SS
n
5
LA
TIT
UD
E(D
eg.)
8o
SS
8
mm
mm
mm
rn
mrn
^
R¥
»s¥
fK:x
-s-
r\
.5
m
5JJ o sn
<3>
X
«» §
.a «>)
01
I
«•
§ it !? CD
cn
/»
:b. 2 % r-
•>1 II i
I CO
os
LA
TIT
UD
E
8o
»O
Io
'
iO O(O o
I <l»
o
LA
TIT
UD
EI Ul
oat
o
'
«o
o
0 "0 1 r-
-x)
tn 7^
7^
09 ? s tS 5 J
?S
C7t>
)
Ik^
01
-90
-ItO
-♦0
•40
Xo»osp»£Kii fbTsirrifii. (volTs")
UT«6
VrI "*V^—;•V I
.- •J'r.X . .. ^ f^TV V. V
LONGITUDE
UT«6
LONGITUDE
;2o/fV
D)?<FT"
UT*I8
wXl -
LONGITUDE
UT-18
•-.t; ••&•••
LONGITUDE
: 90
)/^ too m/^
£d?UlAi^?<
/,
00
LOCAL TIME
60 KV
(c)
f.i
Z«I.O 20 KV
S00
LOCAL TIME
LOCAL TIME
2 = 1.0
z«l.0
• 18
ATV- SIS K
y^;i^«n/5
AT^ ^/5*o K
V i/oc M/s
Figure 2
V'*'
asLii^^)y
\^o KwA
solar, ohl^12 Z--4.0 20 KV
00
LOCAL TIME
60 KV
^tc/ (b)
'9.
LOCAL TIME
;iow
2 *-4.0
00
LOCAL TMKIC
Z«-4.0
,« 7Z 3d)K
-v/VoK
Tl ^ 3<jK
V loomf^
Figure 3
day=83021 TlGCM Ne^trol 7emperolur« (deg k)LTT = 5.0 2P = 2.0
i \ \ V\ V\ >/V • \ / \ \ \ \ ^ I /
i- \ \ 1 V I
500 m/s-occ "^i^e
History«R0BLE/RGPS9 jADED9
A
de2 ort>it-8121(S)
18
U32e-M)3
1 1 4^+03
h
9.60e-t^2
?
t
Perimeter latitude—37.5 (tag
DE-2/GBFPIAVERAGE NEUTRAL WINDS
DEC 1981
305 M/S
NCAR/TGCMMODEL PREDICTIONS
\ \ s S , yyiV. t - "fji/
11=00
333 M/S
A"./ I ' ' I ' ' /^\
A?
\ \ N- - ,\ V-,
\^' *-^ ' i. • ' • • . i;.5> / ^->--1 " y
ls>0 KV '
UT«o ]
-90
-120
(o)
UT.|2
-30
X % ^
t. • / •- • •" ' •• • \> • " ^ - •# • T f A \ "-«0 / ^ . • • # • * \
X # I » V s. / '20
Heo
tONGITUOe
V ^ ^
"30) KM
|uT.6^-30
-/
r . \^t / ^ r-*'' *
Cb)-180
longitude
-90 -. * ' ^ /Ilr^ *
• • • • ^ A/ I , ♦
v/ A'' 'i/ili;;-eo
(c)
a-190
LONGITUDE
if90 -so
-120
(4)-180
LONGITUDE
TI OAt FbHe-iHd S ^PSSSN atJt. I9tcl
gu-l
^RFAce ^
;rA/Aigr/gAl5 (^emi-DiiARhlhL. ^
2-2.
a-^p-d ^
^Pe<LtFy AMpUTUOcS
and P/fASfi"5
fciKt^es i v/A^-ijrcs - s*fMO/fs
ADt>£3^
(F^)R6£S s't: al. ./953.')
MAJOR CONSTITUENT TRANSPORT
The three major neutral constituents of the thermosphere - Oq >^ -^2 " consideredand used to define the ma<ss mgLving fatio pf rnn«gt.i|,iipnt t as
rpi = Tii m, Ey=i
-1
where n,- is the number density of the 2th species, with i = 1, 2 and 3 corresponding,respectively, to O2^ O , and N2', rn- is the mass of the i th species. We furthermore definemixing ratios of O 2 and 0 as the vector
V'O.
and therefore by definition the N2 mixing ratio is obtained by — 1 - V'Oo ~ •
+ e. d
dz
^ rt=-e'r^ ^ m 00
0.25
a^L]kdt
K{z)e
dz IUn.
OtFFu^tci)V
+ S-R.
/TDfty f V£^.]At>V
d 1 , 1 dmV • + w
oz
Upper Boundary Conditions
\t the upper boundary condition, diffusive equilibrium is assumed so that L ^ = 0.
Lower Boundarv Conditions
At the lower boundary, we utilize the observation that the atomic oxygen concentrationi. (0 ) peaks near 97 km and assume that dn {O )ldz =^0. This assumption and conserva-
tion of total oxyg^ atoms implies "oxygen atoms implies
d
dz ^2 — A -I- ^2 = constant
6— P}^CTcT>i56cA.iP,TlcN
^ ^ ^ m > O^. + H
EClui/^CX -EARTH
UT = 12.00 3^90. I I —r-T
60.
30.LJO3f- 0. -
-30.
-60.
-90.
Z = 2.0
-tao. -150. -120. -90. - 30. 0. 30.
LONGITUDE
90. 120. 150. 18C
UT = 12.00 ia.0
90.
60.
30. -
I- 0. W
-30.
-60. ^
-90.-180. -150. -120. -90. -60. -30. 0. 30.
LONGITUDE
400
Z = -4.C
60. 90. 120. 150. 180.
100 M/S
^ n, (0 m/:
^ ^ W/s
«CR»DldA/A«. U)iNrs fM/$\riELD-* *•
• • • • I• • » » %%♦ »o , * %
« % « • « %
nuK
»<
\
«?• •• 9
^tiAL, Ufin!> /<h/s\riELO«U ^ ^ 1T.5N
*. PvSo
•
10C*L 1l«tm.mt cPi<M> mimrn. m • »«it.>i*
ON(S^
n
v*M'o\
/JM-
/O'a
y\)./
(Cfe)N
.ON
N^
9\3
N
T
N4S»)H
(fy\?A^
.1M
WP^^Xi.
I K/V
Neutral-Neutral Coastitaent Reactions and Rates used in the Model.
nCs) + 02
sCd) + Oj
f/(^S) + li/0
N^D) + 0
NQD) + t
N(^D) + NO
NCD)
NO +lkv
NO +ky\t,.
O + 0 +M
O + 0, + M
Reaciioas
fix
03
A
07
A
Tfl
T2
NO + 0 + lAeV
NO + 0('D) + l.84«l'
N. + O + i.«SeV
NCS) + 0 +2.38eV
N(*S) + e +tMeV
N2 + O + S.63<V
N{*S) + hv
WfS)+0
m* + e .J
O n+ O
Oi + M
\iO.
C
MINOR CONSTITUENT TRANSPORT
±-Fdz •" m
Molecular and Thermal Diffusion
Y ' LJdz
Transport Source &
Sink
5^1 dmdz m dz
Eddy Diffusion
where
= gravitational forces + thermal diffusion -h frictional
interaction with major species
Upper Boundary Conditions
Diffusive Equilibrium:
dz "
Lower Boundary Conditions
N {^S) Photochemical Equailibrium
NO Specified Mass Mixing Ratio
V-m =<5
m
i.-D <^Lo5^L
I
200 300 400 500 600 TOO 3 4 5 6 7 8 9 10 11 12 13 14 15 |6TEMPERATURE CK) LOG.o (Owtit,, cm"')
' M I I I I M I M I I I M I I M I I I U
I 2 3 4 5 6 7 8 9 10 II J2 13
L06|o (Density; cm"')
Nrs) :
3.0 4.0 5.0 6.0 7.0
LOG|o (Densityj cm'^)
ISO m
150 m
PHOTOEiKTFRONHEATMG
HEATMG90WHEUVML
CHEMISTRY
HEATWG iWn COUSIONS
4
NEATMGOleOOMBMATION
MMOR
•PECCSIMFFUSION
N(«0).MrS)NO
MEATMQ NBiTRAI^CUTRALCHEMSTRY
iir(K)EQWHO]/i (STdRiM - ^a\sr ^
7cKyf — fi-OKV
TICCU NEUTRAL TCMPnUTinK (BBC K) 4. 5/^TJT - 0.00 ZONAL MEAN (Diftamn) r\
1YCCM 02 NUMBER DENSITY (CM-3) M 3CC/^m « 0.00 ZONAL MEAN (X Differcoec) 'C
-90 •60 -90 • »Uimsx (KG)
k;
M
^CCII N2 NUMBER DENSITY (CM-3) ^bOCTftVT - 0.00 ZONAL MEAN (% Difference)
7 //'/r-.
UTirUDE (DEC)
-30 0 »UT1TUDE (DEC)
„ _ 0 NUMBER DENSITY (CM-3)or - §.00 ZONAL MEAN (X Difference)
UT1TUDE (DEC)
l\).
FIGURE 6
(t)
r
/
O + EQUATION WITH HORIZONTAL AND VERTICAL TRANSPORT
dn
at- Q + Ln = - SZ • nV 1
•where V =Y^+V^
b •^ (ff - SZ p,) +i •uPi1/
B•E Xb
72?
"b
now, —V • nV0= b^ d ^ g-6D 5 r + — n
az "
(^•u)n S. b- b.' S.{b ' u n)
IZ'v^=B X E •SZ(«/B2)
Upper Bcwimdarv Comdations
Mixed boundary condition
-b.^Djm,-
52 ' ifc
Lower Boundary Conditions
Photochemical equilibrium
n (E XB),n + n {b'u)b^ H ^
n=Q/L
andNQ-*-
Once the O"^ distribution is determined the 0 ^ , N^ , N'^ and NO"^ equations are solvedsimultaneously assuming photochemical equilibrium with the O'^ distribution. From thechemistry specified, the production and loss terms are equated and a fourth order equation for
can be derived:
where
n, = n (0+) + n {O^ ) + n {N^ ) + n (iV+) + n {NO'')
Oj = a, (ttj ^ + ttj (7) - ttj Oj a, (f +(?)
O2 — EC •*" Ofj (o^2 E ^ ttj C ) ) —Q!| Of2 ^ —Qfj Qfj B —OC2 Qf3 A
<t 1^ —ot| [EO {^F ) + DC + BE —0C2 E (j4 +Z? ) —03 C +5)
Aq —EC (A + ^ )
A (0+) n (ATj) + n {N+) n (Oj) + fign [NO)
B = ,, (Oj+ ) + *1 n (0+) n (Oj) + itg n (N+) n (Oj)
C =k^n {N (*5)) + fcj n (NO)
D =.j{N2+)
=tj« (0)
F = n (0+)
G =n {N+).
The qfuartic equation can be solved exactly yielding four roots. Three of the roots are imaginary or not physical leaving one real and physicaJ root, for the electron density, . Oncen, is known, the ion number densities can be determined from
n (N2+) = D/iE +a^n,)
n (02+) = B/(C7 +a2nj
n [N0+) = (X + ED /{E +a^n,) + CB /{C + n, Ma^ n.)
(Ar+) = n {N+)/({ks + ifc,) n (Oj) + Ag n (O)).
UT=12; 0
t
-tftO. -120
ilo9io(n,\em-*))
0.
longitude
12LOCAL TIME
17.5N
400.
500.
200.
100.
oQ-
5
4
1
0
-1
-2
-3
-4
-5
-6
-7
LOG TGCM ELECTRON DENSITY (HIST) (CM-3)76080 EQSN03.N04 UT=19.00|sLT=16.00l LON= -45.00
- 400
88
- 300
- 200 o
- 100
-90 0 30GE0G LflT (DEG)
TIGCM OUTPUT
• Neutral gas temperature, Tn
• Neutral winds, U, V, W
• Height of constant pressure surface, h
• Neutral composition and density
Major - O, O2, and N2
Minor - N{^D), N(*S), NO, He, and Ar
• lom coamupositiom
0+, N0+, 0+, and N+ Enj =
loiQ temnperaiture, Ti
E}lectron temperature,
• Global dynamo TT£ —
e , J
CO
Eo
ooO)
E-x:
tsl
0
- ^ 1,1——^——A
1 -
, JVw
Jt L_
—- « • « r~»
' . i— ' • « '—• '•
)r-^
A A- - « — -—t , « . .—^—• • •—
W lOOO
U1
<
12 14
Univer&al Time
• Cbft
1900 M/S -> (d)
TtfC
.
2900 M/S
2900 M/S>
llJ
<
UTs 8:90 MUt 1WC I70CI< irr. U-'iO iCCJH TMC
%
1400 M/S
UT = 15:30 «rca0:90
X
MOO M/S
B
2400
1600
800
00 2 4 6 8 10 12 14 16 18 20 22 24
UT
uTse^so
7^
%^(4co
UT = 15=30
IjJ -u
7^ 3oeK
UT « 12*30
UT = 20=30
LOCAL TIME
4
LOCAL time
12
"TjJ ^ CooK3S&K
TIGCM INPUTS FOR MARCH/APRIL. 1979
83 64 85
DAY OF 1979
ELECTRON DENSITY (CM-DAY=79081 UT=15.00 ZP=
3)
NEUTRAL TEMPERATURE (DEG K) ^DAY=79081 UT= 16.00 ZP= 2.0
-900 6 12 18 0
LOCAL TIME
1 1 I I
1050. 1425. 1800."T T"
.-1 i 1 1 > 1
ni
7
KP
079 DAY
i r.1
89
ATOMIC OXYGEN (CM-3)DAY=79088 UT= 6.00 ZP=-4.0
ji;
i'
SETA-2 ORBIT 1026 DAYS 82194-82195 AVE ALT 22440( 261 POINTS FROM UT 22.75 to 24.23)
90
60 -
OW 30
Q 0D
H-30
;3-60 I-
-90
.,.X23.6
-180 -120 -60 0 60
LONGITUDE (DEG)120 leo
11x10-•13
10X10-•13
CO9x10- 13
SIo 8x10-•13
\
2: 7x10-•13
o
6x10-•13
>-
h-5x10-•13
CO 4x10- 13
zLiJ 3x10- 13
o2x10- 13
10"13
LOCAL TIME
ALTITUDE
22.8 23.0 23
1
.2 23.4 23.6
UT (HRS)1 1 1
23. B 24.0
1
24.2
1 1 1
1 1 1
22
1 1
201612
1 1 1
10
1 1
86 2
1
275 260 245 230 215 200 185 185 215 245 275
SETA-2
(solid)
MSIS66
(dashed)
TIGCM
(dash-star)
SETA~1 ORBIT 180 DAY 79086 AVE ALT 201.32( 204 POINTS FROM UT 19.99 to 21.14)
"T ' ' 1 ' ^
20 30
U 30
f—30\
21.03
-180 -120 -60 60 120 180
11x10- 13
10x10" 13
n9x10-•13
21O 0x10" 13
£ 7x10 13
o13
6x10>-
»- 5x1013
cn 4x10-•13
zLiJ
o3x10- 13
2x10-•13
10'-13
LONGITUDE (DEC)
20.0 20.1 20.2 20.3 20.4 20.5 20.6 20.7 20.8 20.9 21.0 21.1
U1 (HRS)
I I I I 1LOCAL TIME22
ALTITUDE245 230 215 200
2016 12
I
185
10
J_ J L
170 170 185 200 215 245
SETA-1
(solid)
MSIS90
(dashed)
TIGCM
(dash-star)
PCnC
EN
To
rto
tal
po
ints
Pcn
ccN
To
rto
tal
po
ints
Su
UkJt ^
0 ,4^—
•iti
?•
+
? .^ . . . .+ TiPiS^6ci^ A'—-^ '
tf4^ ^ ••««^ '̂ «~ .
^ ^/^%. I ^/^X. ®
J'̂ *»««^*^*'̂ '*'<» •<i»
f I •! |l^ I < r
^ g, . ♦