Presentation is loading. Please wait.

Presentation is loading. Please wait.

Solar Wind Induced Escape on Mars and Venus. Mutual Lessons from Different Space Missions E. Dubinin Max-Planck Institute for Solar System Research, Katlenburg-Lindau,

Similar presentations


Presentation on theme: "Solar Wind Induced Escape on Mars and Venus. Mutual Lessons from Different Space Missions E. Dubinin Max-Planck Institute for Solar System Research, Katlenburg-Lindau,"— Presentation transcript:

1 Solar Wind Induced Escape on Mars and Venus. Mutual Lessons from Different Space Missions E. Dubinin Max-Planck Institute for Solar System Research, Katlenburg-Lindau, Germany

2 Plume of PI Plasma sheet lobes BL Ionospheric (polar) wind SOLAR WIND INDUCED ESCAPE E B MEX / ASPERA-3

3 SOLAR WIND INDUCED ESCAPE

4 COLD IONOSPHERIC IONS FAR IN TAIL Cold ionospheric ions POLAR WIND

5 SOLAR WIND INDUCED ESCAPE

6 ESCAPE OVER REGIONS WITH STRONG CRUSTAL FIELDS UV background

7 PLASMA SHEET P (ASPERA-3) P (MARSIS) dyn M dayside nightside some part of momentum thermal pressure

8 ESCAPE THROUGH PLASMA SHEET IS CONTROLLED BY SW VARIATIONS K is momentum transfer factor (~0.1)

9 CMEs IMPACT VENUS AND MARS

10 MERCURY VENUS 4-5 June hours hours CME PP P M ~29 nPa P M ~5.3 nPa

11 MARS (MARSIS DATA) Sequential plot for local |B|: 9475, 9481, 9482, 9487

12 MARS (MARSIS DATA) Sequential plot for ionospheric peak n e : 9475, 9481, 9482, 9487

13 VENUS MARS Different modes of ELS

14 - OTHER OPEN QUESTIONS?

15 - ION FORESHOCK ? (There are no reflected protons upstream of the nose of the Martian BS. Ion foreshock lies entirely downstrem of the subsolar point) - HOT OXYGEN CORONA? (There are no ASPERA observations of oxygen ions which could be reliably identified as originated from hot oxygen corona)

16 ’FILAMENTATION’ OF PLASMA FLOW AROUND MARS 2050 2100211021202130

17 PLASMA FILAMENTATION IN MULTI-FLUID AND HYBRID SIMULATIONS Z, Rm Y, Rm x=0 SW MULTIPLE SHOCKLETS PROTON NUMBER DENSITY X, Rm PROTON NUMBER DENSITY XZ-PLANE YZ-PLANE

18 MAGNETIC FIELD IN IONOSPHERE

19

20 IONOPAUSE OR… ? density altitude

21 WHAT IS AN OBSTACLE FOR SW ? ALFVEN SPEED PILEUP BOUNDARY PHOTOELECTRON BOUNDARY

22 MARSMARS EARTHEARTH INVERTED V STRUCTURES ON MARS AND AURORA?

23 DO WE UNDERSTAND CLEARLY WHAT IS INDUCED MAGNETOSPHERE? SOLAR WIND WITH ALIGNED IMF

24 VENUS EXPRESS OBSERVATIONS

25 FIELD CONFIGURATION (POLOIDAL FIELDS) Without flow With flow With flow and leakage of dipole field outwards

26 REVERSED DRAPING OR WRAPPING EFFECT

27

28 CURRENT PATTERN

29

30 E + - hemisphereE - - hemisphere

31 CONCLUSIONS WHILE THE IDEA OF AN INDUCED MAGNETOSPHERE AT FIRST SEEM STRAIGHTFORWARD, IT IS NOT A PARTICULARLY WELL-CONSTRAINED CONCEPT WHEN APPLIED TO VENUS AND MARS WE NEED A MISSION WITH ADEQUATE PAYLOAD TO ADDRESS THESE QUESTIONS (MAVEN ?)

32 BACKUP Launch, 18 November 2013 3-axis-stabilized, sun-pointing spacecraft 75 o inclination, 4.5-hour period orbit Five 5-day “deep dip” campaigns with periapsis altitudes down to the homopause (~125 km). Nominal periapsis: ~150 km Eight science instruments, grouped into three packages

33 The MAVEN Science Instruments Mass Spectrometry Instrument Remote-Sensing Package Particles and Fields Package

34 BACKUP

35 ESCAPE FLUXES AS A FUNCTION OF SW FLUX

36 OVER CRUSTAL FIELD REGIONS IONOSPHERIC EROSION EROSION IS TRIGGERED BY SOME UNKNOWN FACTORS 5th Alfven Conference, October 5, 2010, Sapporo, Japan

37 ELECTRON ACCESS VERSUS TOTAL CRUSTAL FIELD E= - V x B SW By < 0 ALT, km By (IMF) > 0 By(IMF) < 0 B (400km),nT Electron Flux - B y_IMF < 0 supports electron access to lower altitudes Dubinin et al., AG, 2008 5th Alfven Conference, October 5, 2010, Sapporo, Japan

38 B y (IMF) is negative MAGNETIC FIELD AT LOW ALTITUDES

39 B y (IMF) is positive MAGNETIC FIELD AT LOW ALTITUDES FLUX ROPE (Zhang et al. 2012) OR ELECTROJET

40

41

42

43 - Thermal escape of hydrogen is the dominant process Mean flux ~ 1.6 x 10 cm s 8 -2 ~ 2x 10 26 s ~ 10 26 s ?


Download ppt "Solar Wind Induced Escape on Mars and Venus. Mutual Lessons from Different Space Missions E. Dubinin Max-Planck Institute for Solar System Research, Katlenburg-Lindau,"

Similar presentations


Ads by Google