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