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Институт космических Институт космических исследований Российской исследований Российской
Академии наукАкадемии наук
Необычная магнитосфера Марса – Необычная магнитосфера Марса – сопоставление результатов сопоставление результатов
предшествующих и последних предшествующих и последних исследованийисследований
М. ВеригинМ. Веригин
Пятая конференция ОФН 15«Физика плазмы в солнечной системе»
812 февраля 2010 г., ИКИ РАН
СодержаниеСодержание
Mariner Mariner 44 , , Марс 2, 3, 5 – ранние измеренияМарс 2, 3, 5 – ранние измерения
МарсМарс 3 3 – первые наблюдения намагниченности марсианской коры – первые наблюдения намагниченности марсианской коры 21 января, 21 января, 19721972
о магнитном моменте Марсао магнитном моменте Марса
особенности околомарсианских плазменных границособенности околомарсианских плазменных границ::
- стабильность ударной волны у терминаторастабильность ударной волны у терминатора;;
- отсутствиеотсутствие VV22 инвариантности магнитопаузыинвариантности магнитопаузы;;
- очень большой отход ударной волны от Марса при малых очень большой отход ударной волны от Марса при малых MMaa
в солнечном ветре;в солнечном ветре;
- олияние неоднородной намагниченности марсианской коры на олияние неоднородной намагниченности марсианской коры на положение магнитопаузыположение магнитопаузы;;
конкуренция двух механизмов ускорения ионов в магнитном конкуренция двух механизмов ускорения ионов в магнитном хвосте Марсахвосте Марса
об источниках ночной ионосферы планетыоб источниках ночной ионосферы планеты
Mariner 4, Mars 2,3,5 observationsMariner 4, Mars 2,3,5 observations
Mariner 4, July 15, 1965 Марс 2-3, 5, 1971-72, 1974
Martian bow shock Martian bow shock discoverydiscovery
Martian Martian magnetospheremagnetosphere discoverydiscovery
multiplemultiple bow shockbow shock crossingscrossings
Mars 2
1 - 17.12.71
2 - 08.01.72
3 - 12.05.72
Мars 3
4 - 15.12.71
5 - 09.01.72
6 - 21.01.72
7 - 21.01.72
Мars 5
8 - 13.02.74
9 - 20.02.74
10 - 22.02.74
11 - 24.02.74
• Strong (~27 nT) and regular magnetic field in the vicinity of Mars 3 closest (~ 1500 km) approach to the day side of the planet
Mars 3 magnetospheric observationsMars 3 magnetospheric observations
Dolginov et al., Doklady AN SSSR, 207, No.6, 1296-1299, 1972
Dolginov et al., JGR, 81, No.19, 3353-3362, 1976
• Originally interpreted as an evidence of planetary dipole magnetic field Mm = 2.4x1022 G cm3
• Later Russell et al. (GRL, 5, No.1, 81-84, 1978) inferred that“…observed magnetic field was draped over the Martian obstacle as expected if the field were simply shocked and compressed solar wind magnetic field.”
• Magnetic field direction has discon-tinuity around the Mars 3 closest approach region (orange arrows)
Inconsistency with simple IMF drapingInconsistency with simple IMF draping
• Magnetic field direction is inconsis-tent to those one expected for simple draping in the closest approach region
- 8 - 6 - 4 - 2 0 2 4
Y as e, R m
- 2
0
2
4
Z as e, R m
from Sun
Mars 3, Jan. 21, 1972
- 8 - 6 - 4 - 2 0 2 4
Y as e, R m
2
0
-2
-4
X as e, R m
from N orth
Hence : “…Mars most probably possesses a small intrinsic field magnetosphere.”
Slavin & Holzer, JGR, 87, No.B12, 10285-10296, 1982
but:
What was below Mars 3 on Jan.21, 1972 ?What was below Mars 3 on Jan.21, 1972 ?
Mars 3 observed strong
and regular magnetic field
exactly above the region of the
strongest magnetization of the Martian crust
Mars 3 orbit Jan. 21, 1972 projection to surface
0 90 180 270 360East Longitude
-90
-60
-30
0
30
60
90
Lat
itude
0102030405060708090100110120130140150160170
B , nThor
0
0
Lat
itude
Hor
izon
tal m
agne
tic f
ield
Con
nern
ey e
t al
., G
RL.
, 28
,
No.
21,
401
5–40
18,
2001
Tot
al m
agne
tic f
ield
Do MGS crustal field direction corresponds Do MGS crustal field direction corresponds to those one observed by Mars 3 ?to those one observed by Mars 3 ?
Connerney et al., 400 km , B horizontal, 15o averaged
M ars 3
Mars 3, 1500 km , Jan. 21, 1972
YES !YES !
Comparison of Mars 3 magnetic field with those one of MGS provides evidence that Mars 3 really detected the magnetic field of Martian crust in the early 1972.
Verigin & Slavin, EPSC 2006-A-00385.
This observations was not properly interpreted before MGS crustal magnetization discovery.
Mars Global Surveyor :
Mm 2 · 1020 гс · см3 (Acuna et al., 2001) ???
with Bequat 0.5 nT
0 10 20 30 40 50N o . o f sp e ctra l h a rm o m ics
1
10
100
1000
Sp
ect
ral p
ow
er,
nT
h = 0 km
h = 120 km
but Bequat ~ 10 nT (Arkani-Hamed, 2001)
Mm ~ 4 · 1021 гс · см3
Phobos 2:
Mm 8 · 1021 гс · см3
magnetopause model by Verigin et al. (1997)
Prior to Phobos 2: Luhmann et al., 1992
On planetary magnetic moment of MarsOn planetary magnetic moment of Mars
On planetary magnetic moment of MarsOn planetary magnetic moment of Mars
There is an essential dipole component exists in the multipole moment of planet Mars
Further methodology development is necessary for its accurate determination, including consideration of current systems produced by solar wind – Mars interaction
Nothern hemisphere:
“TO THE PLANET”
Southern hemisphere:
“FROM THE PLANET”
Mars Global SurveyorMars Global Surveyor : Connerney et al., 2001
Phobos 2 – detailed BS and MP Phobos 2 – detailed BS and MP position dependencies on position dependencies on VV2 2
Martian magnetotail diameter
D ~ 550 (V2 )-1/5.9 км
similar to geomagnetic tail compressibility
Distance to terminator bow shock
R ~ 6000 (V2 )-0.02 км
practically independent on the V2 !!!
Phobos 2 statistics of the bow shock and magnetopause crossings
Martian magnetopause shape and variationsMartian magnetopause shape and variations
-5 -10X, 103 km
.1
.25
.631.64.010.0
V 2, nP
M AR S
Y, 103 km
-10
10Trotignon e t a l., JG R , 24965, 1996
Verig in et a l., JG R , 2147, 1997
V ignes e t a l., G R L, 27, 49, 2000
Phobos 2 V2 dependent Martian magnetopause model
-5000 0 5000
2000
6000
-5000 0 5000
2000
6000
-5000 0 5000
2000
6000
0 . 1 < V 2 < 0 . 3 n P
-5000 0 5000
2000
6000
0 . 9 < V 2 < 1 . 1 n P
1 . 8 < V 2 < 2 . 2 n P 2 . 5 < V 2 < 3 . 5 n P
P l a n e t o c e n t r i c d i s t a n c e , X a s e , k m
Pla
neto
cent
ric d
ista
nce,
a
se ,
k
m
MGS V2 dependent Martian magnetopause model
Ve
rigin
et
al.,
Ad
v. S
pa
ce R
es.
, 3
3,
12
, 2
22
2,
20
04
Martian magnetopause is not of V2 invariant Stagnation of the magnetopause nose position and increase of its curvature radius with increasing of V2 are explaining V2 independence of the bow shock terminator position, found by Phobos 2 data
3/4
408.022
22
649.02018.02
22018.02
)(17146
)(41
))(794)(3958(2
)()(3958
V
ZY
VV
ZYVX
Distant BS excursions at small solar wind Distant BS excursions at small solar wind MMa a valuesvalues
Upstream solar wind on March 24, 1989
Unusually distant Martian bow shock excursions were initiated by extremely small upstream V2 and Ma values
Verigin et al., Sp.Sci.Rev.,111, 233, 2004.
Y 2a se + Z 2
a se, 10 3 km
X ase, 103 km
M AR S
10
5
-10 -5 0 5 10
t1
t2
t3
S 1S 2S 3
M P 3
M P 2
M P 1
Phobos 2orb it
r, 1
03
km
5
7
10
r, 1
03
km
1
10
Ms
V2,
dyn
/cm
2
1
10
Ma
10 -10
10 -9
20
20.40 20.00 19.40 19.20 U T20.20
4
7
10
r0
rs
rsc
rbs
52.5 37.9 23.5 10.1 , deg
BS BS BSf)
g)
h)
i)
j)
Modeled typical (BS3, MP3) and distant (BS1, MP1) positions of the Martian bow
shock and magnetopause
Influence of the Martian crustal magnetization Influence of the Martian crustal magnetization
on the magnetopause positionon the magnetopause position
Localized Martian crust magnetization increases downstream magnetopause height by 500-1000 km additionally.
0 90 180 270 360E ast Long itude
-90
-60
-30
0
30
60
90La
titud
e
0
20
40
60
80
100
120
140
160
B , nTr
0 90 180 270 360E ast Long itude
-90
-60
-30
0
30
60
90
Latit
ude
0
20
40
60
80
100
120
140
160
B , nTr
B h , nTAll V 2 , B h(400km ) < 10 nT beneath M Pb stream line
B h(400km ) > 40 nT exists beneath the end of M Pb stream line-10000 -5000 0 5000
X mso , km
5000
10000 mso , km
0.5 < V 2 < 1.4 nP
= D
atan( D2 ro (ro -x ))
D = 19432ro = 4179
-10000 -5000 0 5000
X mso , km
5000
10000 mso , km
D = 23951ro = 4470
~ 1000 km
Phobos 2 orb it
0
60
120
180
240
300
180 120M P zenith angle, deg
V 2 < 0 .5 nP
0.5 < V 2 < 1 .4 nP
V 2 > 1 .4 nP
Equatorial magnetotail diameter dependence on the longitude of the upstream terminator (Phobos 2)
Increase of the magnetopause height over magnetized regions (MGS data)
Verigin et al., Adv. Space Res., 28 (6), 885, 2001; 33(12), 2222, 2004.
Martian magnetotail magnetic field and Martian magnetotail magnetic field and plasma arrangement by IMFplasma arrangement by IMF
Schwingenschuh et al., Adv. Space Res., 12(9), 213, 1992
Yeroshenko et al., GRL, 17, No.9, 885, 1990
Mars Express
ASPERA 3 experiment
Barabash et al.,
Science 315, 502, 2007
plas
ma
shee
t
Loss of planetary ions through plasmasheetLoss of planetary ions through plasmasheet
Phobos 2, Feb. – Mar. 1989, High SA
Ф ~ 5.1024 ions/s
Verigin et al., Planet. Space Sci. 39, 131, 1991
MEX, May 2004 – May 2006, Low SA
Ф ~ 1.6.1023 0+/s + 1.5.1023 02+/s +
+ 0.8.1023 C02+/s ~ 4.1023 ions/s
Barabash et al., Science 315, 502, 2007
Direct Simulation Monte Carlo (DSMC) + 3D Mars Thermosphere General Circulation (MTGCM) modeling
Valeille, Combi, Tenishev, Bougher, Nagy, Icarus, doi: 10.1016/j.icarus.2008.08.018, 2008
Both experimental estimates are in qualitative agreement with variation of the planetary ion escape rates within solar cycle, although the escape of Martian ions integrated over near-planetary region is only the minor part of planetary ion escape rate (ФhighSA ~ 2.4.1026 0/s, Valeille, et al., 2008). Direct measurement of total ion escape rate are highly welcomed.
Hot oxygen corona is the Hot oxygen corona is the mainmain channelchannel of of Martian ions loss – how to measure it?Martian ions loss – how to measure it?
0 10 20 30 40 50 60tim e from BS, m in.
1.0
1.5
T /
Tr
0 10 20 30 40 50 60
1.0
1.5
N /
Nr
0 10 20 30 40 50 600.9
1.0
V /
Vr
0 10 20 30 40 50 600.9
1.0
0 10 20 30 40 50 60
1.0
1.5
0 10 20 30 40 50 60tim e from BS, m in
1.0
1.5
- Bm s/ Bsw < 2.3 - inbound- outbound
- Bm s/ Bsw > 2.3
),,(2
)1(),,(
2
sincos)1(),,(
2
10
02
00
00
rLV
prLvrLVU
),4
sincos)1(3
4
)1cos3)(1(2(
14
22
2
2
00
0 LLLV
drrrL nn
cos
22 )sin(),(
iL
r
H
O
O
HHO e
r
r
r
r
M
Mrnrn
3
0
2
0
5
31310)()(
Upper lim it, SAmaxPhobos 2, preshock
SW deceleration
Solar wind pre bow shock decelerationPhobos 2, High SA
Comparison with DSMC+MTGCM modeling
Li ~ 4x106 km !
total pick-up ion flux F < 2·105 (104km / r ) cm-2s-1
pick-up ion number density
cm-3
kmr,10
1
km/s,V
2n
4sw
Measurements of pick-up ion radial profile, starting from ~ 106 km to Mars, can provide reliable evaluation of the total Martian ions loss rate
Kotova et al., JGR, 102, A2,
2165, 1997
Competing processes of Martian plasmasheet ion accelerationCompeting processes of Martian plasmasheet ion acceleration
1) Magnetic field line stress acceleration
Bjc
VV
,1
),( jBc
LV 2
IIBc
j2 IIci
th
eB
Mc
M
kTv 2~
2~
LkTMc
BeBV II
22~
22
with and
2) Across magnetotail electric field E acceleration
Ion energy increase Ei after its cyclotron diameter 2Rc displacement across the magnetotail ci ReE 2E~
eB
McVeEVMV 2~
B
EcV 2~
Competing processes of Martian plasmasheet ion accelerationCompeting processes of Martian plasmasheet ion acceleration
0.0 0.1 0.2 0.31/B m in, 1 /nT
0
100
200
300
Hea
vy io
n v
elo
city
, k
m/s
V2 > 610-9 дин/см2 V2 < 610-9 дин/см2
Across magnetotail electric field acceleration prevails –”magnetospheric obstacle”
Magnetic field line stress acceleration prevails – “induced obstacle”
II
1 10 100 1000B 2 * B / T1/2, nT3/(103K)1/2
heav
y io
n ra
m p
ress
ure,
dyn
/cm
2
Change of the plasmasheet ion acceleration process take place at that V2 value when magnetopause nose position starts to increase after its stagnation at high ram pressures
Ko
tova
et
al.,
Ph
ys.
Ch
em
. E
art
h (
C),
25
(1-2
), 1
57
, 2
00
0
Martian nightside ionosphere sourceMartian nightside ionosphere source
Phobos 2 electron spectra measurements (HARP experiment) revealed permanent presence electron fluxes of J0 ~ 108 cm-2s-1 in the areomagnetic tail with energies sufficient for ionization of Martian neutral atmosphere constituents
Estimated peak nemax of the night-
side ionization layer corresponds to that one observed by radio occultations of Mars 4,5 and Viking 1,2 spacecraft.
h
nciini
e dhhnhnj
hn )()(3exp)(
)( 0
“Why was the peak of nightside ionization observed in 100% of th s/c radio occultations at but in only 40% of radio occultations at Mars?
The reason may be connected with the partial screening of the Martian nightside atmosphere by a weak intrinsic magnetic field of the planet which is completely absent in the case of Venus”
Verigin et al., JGR, 96(A11), 1991Haider et al., JGR, 97, 10637, 1992
Martian nightside ionosphere sourceMartian nightside ionosphere source
Leblanc et al., JGR, 111(A09313), doi:10.1029/2006JA011763, 2006
Martian nightside ionosphere source:Martian nightside ionosphere source:comparison with subsequent observationscomparison with subsequent observations
Magnetization of Martial crust that partially screens planetary atmosphere was really found…
Acuna et al., JGR, 106(E10), 23400, 2001
Comparison of nightside low altitude electron spectra measured by MEX/ASPERA 3 and MGS/ER (thick line) with Phobos 2/HARP (color) ones used for nightside ionization calculations
Bra
in e
t al.,
GR
L, 3
3, L
0120
1, 2
006
Dub
inin
et a
l., P
l.Sp.
Sci
., 56
, 846
, 200
8
Comparison with SPICAM UV spectroscopy measurements aboard Mars Express
Detailed multi-ion nightside Martian ionosphere model is available now, considering e-impacts and galactic cosmic ray ionization until planetary surface
Haider et al., JGR, 112(A12309), doi:10.1029/2007JA012530, 2007
Спасибо за внимание !
Спасибо за внимание !
Пятая конференция ОФН 15«Физика плазмы в солнечной системе»
812 февраля 2010 г., ИКИ РАН