Multi-Ion Space Plasma Research: Two highlights

Transcription

1 Multi-Io Sac Plasma Rsarch: Two highlights I. Plasma structurs ad boudaris i solar wid itractio with o-magtizd bodis II. Origi of cohrt larg-amlitud was i multi-io sac lasmas K. Saur * Max-Plack-Istitut für Aroomi, KatlburgLidau, Grmay * i clos cooratio with E. Dubii (MPA) ad artly with A. Liato ad J. McKzi Multi-Io Sac Plasma Rsarch: I. Plasma structurs ad boudaris i solar wid itractio with o-magtizd bodis MARS Comt Hal-o 1

2 Multi-Io Sac Plasma Rsarch: I. Plasma structurs ad boudaris i solar wid itractio with o-magtizd bodis Itroductio:...History of Mars Plasma Rsarch Two-fluid modl of itractio Numrical rsults Th MP at Mars - a w ty of lasma boudary Imlicatios to ROSETTA, MARS-EXPRESS ad CASSINI Io acoustic was i a Ar-H lasma Thory: Frid t al., 1971; Exrimt: Tra ad Coqurad, 1976 Lft: xrimtal wa attr for diffrt coctratio α. Th itrfrc attr for α 30% is du to th sur-ositio of th two wa mods. Right: has locity of th two io-acoustic mods rsus th coctratio α 2

3 Dust-acoustic was i a Q machi (arka t al., 1996) Dust-acoustic was (Rao, Shukla ad Yu ;1990): h k( T Ti) ( m d d 2 Z ) Diffrtial stramig btw rotos ad α-articls i th solar wid Hlios: Marsch t al., 1982 Ulysss: Nugbaur t al., 1994, 1996 Wid: Stibrg t al., 1996 V α - α Tmoral ariatio of α for o wk of Ulysss data (Nugbaur t al., 1996). 3

4 Solar wid itractio with Mars, Vus ad comts Comt Su hoto ioisatio Solar wid aramtrs: 500 km/s 5 cm -3 5 T T 10 V Mars surroudd by a iooshr Dyamic solar wid ad comt obsratio by Lasco o SOHO 4

5 Th comtary lasma boudaris Hally: Q s -1 IC SW roto caity S: ow Shock MP: Magtic Pil-u oudary IP: Iooaus comtoshath magtic il-u rgio magtic caity Plasma boudaris at comts ad Mars Hally S MP S MP IP IP MARS km km 0 5

6 Scitific ascts of solar wid - Mars itractio Study of fudamtal rocsss of lasma-lasma itractio which ar rlat for may othr situatios: comts, moos (Tita), astroids, Pluto, dust rigs, tc. Mars dhydratio: loss of watr by solar wid - atmoshr coulig; 1-10 m of surfac watr i 4.5 billio yars. Sac wathr: gratio of high rgtic articls, scially by CMEs (o shildig by a itrisic magtic fild). Solar wid scagig of th martia atmoshr > dhydratio Mars Exrss: ASPERA-3 will do global imagig ad i-situ masurmts of: Iflow solar wid Solar wid Outflow latary wid usig Ergtic utral atom camras ad lasma (iolctro) sctromtrs Platary wid 100 to/day 6

7 Scitific ascts of solar wid - Mars itractio Study of fudamtal rocsss of lasma-lasma itractio which ar rlat for may othr situatios: comts, moos (Tita), astroids, Pluto, dust, tc. Mars dhydratio: loss of watr by solar wid - atmoshr coulig; 1-10 m of surfac watr i 4.5 billio yars. Sac wathr: flux of high rgtic articls, scially by CMEs (o shildig by a itrisic magtic fild). History of Mars Plasma Rsarch S MP Our rst iw IP MARS km 0 7

8 Mars-2 obsratios i 1972 (Dolgio ad Grigauz, 1972) S MP Th saccraft crossd th bow shock (S) ad th obstacl boudary (magtoaus MP) Mars-2 obsratios i 1972 (Dolgio ad Grigauz, 1972) [T). S S MP I [A] Variatio of th magtic fild ad th lctro currt I at crossig th bow shock (S) ad th obstacl boudary (magtoaus MP) 8

9 Obstacl boudary i classical MHD modls Th solar wid dyamic rssur is balacd by iooshric thrmal rssur: ρ 2 k T (Iooaus) For T 1 V, a dsity of 10 4 cm -3 is rquird. Th iooshr of Mars is ot ds ough to rach such a dsity at about 500 km whr th obstacl boudary is obsrd. Thrfor, th obsrd boudary is ot a Iooaus. itrisic magtic rssur: ρ 2 2 /2µ 0 (Magtoaus) From th obsrd locatio of th obstacl boudary i a subsolar hight of about 500 km a magtic momt of Mars of about M T m 3 was stimatd. History of th Mars magtic momt From ositio ad sha of th obstacl boudary (MP) a magtic momt of M T m 3 was stimatd. Phobos-2 MGS 9

10 Th Phobos-2 missio i 1989 Th saccraft aroachd Mars dow to about 850 km durig 4 llitical orbits, arly o moth i a circular orbit, aroachd th Phobos moo u to 200 km. It was quid with imortat istrumts for lasma rsarch: magtomtr (MAGMA, FGMM), lctro ad io sctromtrs (ASPERA, TAUS), soudrs for low- ad high- frqucy lasma was Obsratio of th Io Comositio oudary (IC) by Phobos-2 S IC Sigaturs of th IC: - SW roto dsity dcrass - lctro dsity sharly icrass which -bcaus of charg utrality - mas a abrut icras of th latary io dsity: Protos ar rlacd by hay ios. 10

11 Obsratio of th MP/IC i larg distacs by Phobos-2 (1989) ( km) Jum of th magtic fild: MP Chag of io comositio: - SW rotos outsid - latary ios (oxyg) isid S MP IC MP rotos oxyg ios S Obsratio of th MP/IC i larg distacs by Phobos-2 ( km) Jum of th magtic fild: MP Chag of io comositio: - SW rotos outsid - latary ios (oxyg) isid 11

12 Phobos-2 obsratios of th Io Comositio oudary Io Comositio oudary (IC) Dubii t al., 1996 IC UT (h) Mars Global Suryor - its cotributio to Mars lasma rsarch S MGS orbit Most imortat: MGS wt dow to Mars u to about 150 km. Th saccraft carris a magtomtr ad a lctro sctromtr. It crossd th iooaus ad from th masurd magtic fild a momt of M T m 3 was dtrmid. This alu is mor tha o ordr of magitud wakr tha stimatd bfor. 12

13 Th Magtic Pil-u oudary at Mars ad comt Hally IP IP Mars Mazll t al., 2001 magtic caity Comt Hally Nubaur t al., 1986 First attmts to fid th IC i two-io fluid simulatios S IC IP 1D two-io fluid simulatios with latral ffcts h x (R M ) 13

14 First attmts to fid th IC i two-io fluid simulatios 1990 ASTRACT....This boudary is itrrtd as a multi-io cotact discotiuity whr th rotos ar dflctd by th Lortz forc arisig from th rlati motio btw both io fluids. Th magtic fild trats th IC... Aals Gohysica, 1990, 8, (10), Idicatio of thr lasma boudaris from th Phobos-2 obsratios; 1D bi-io fluid simulatios with latral ffcts (aftr MGS) Furthr sts i two-io fluid simulatios First thortical idc of a Io Comositio oudary (IC) i 2D simulatios of solar wid massloadig. (Th rotooaus - a io comositio boudary i th magtoshath of comts, Vus ad Mars; Saur t al., GRL) Imrod 2D two-io fluid modl (iclusio of thrmal ffcts) showig th Magtic Pil-u oudary (MP) at th sam locatio as th IC. (Th atur of th Martia obstacl boudary; Saur ad Dubii, Ad. Sac Rs.) Joit Phobos - MGS ISSI workshos: Mars book (Kluwr) Sac Scic Riw will b ublishd i srig of

15 Thortical mthods for dscribig multi-io lasmas Liar thory: Disrsio of LF multi-io was (fluid ad kitic modls) Statioary oliar was: Oscillitos - a w ty of solitary structur, origi of cohrt was Numrical simulatios: (1) 1D ad 2D bi-io fluid simulatios (2) 1D ad 2D bi-io hybrid cod simulatios Th two-io fluid Hall-MHD modl Protos () ad hay ios (h) ar cosidrd as sarat fluids which ar could by lctromagtic forcs Elctros ar mass lss Charg utrality: h No collisios Th systm of basic quatios cosists of - 2 cotiuity quatios - 2 momtum quatios - Faraday s law - Ergy quatio for lctros 15

16 Solar wid flow though a hay-io cloud, siml modl of lctrostatic itractio solar wid o magtic fild Situatio at t0: hay-io cloud cold ios, warm lctros: ( x) 0 t x 2 ( x) ( x ) E t x m h ( h hx) 0 t x 2 h ( h hx) ( h hx) E t x m 1 E - x h m 0 P ( x P )( γ - 1)P x 0. t x x x x h x ( x h hx )/ Solar wid flow though a hay-io cloud, siml modl of lctrostatic itractio Th itractio strogly dds o th Mach umbr of th icomig lasma flow 16

17 Solar wid flow though a hay-io cloud: siml modl of lctrostatic itractio Sursoic flow: M s 2.0 Solar wid flow though a hay-io cloud: siml modl of lctrostatic itractio Subsoic flow: M s 0.5 Th flow is acclratd withi th cloud: Laal ozzl ffct 17

18 Solar wid flow though a hay-io cloud: hybrid cod simulatios Sur- Sub- Alfic flow: M A Th flow is acclratd withi th cloud. Motschma, Saur ad Roatsch, 1992 Fluid dscritio i th mass-lss lctro aroximatio ( t ) ( P m ) m ( E x) Amr s law is usd to limiat E x µ 0 j x aroximatio of mass-lss lctros: m 0 j - h h Elctro-roto lasma - µ 0 1 x Two-io lasma h 1 - µ 0 x charg utrality: charg utrality: h 18

19 19 µ µ ) 2 (P ) P m ( ) m ( t - I µ µ h h ) 2 (P ) ( ) P m ( ) m ( t - I x charg utrality: h Equatio of motio i siglad two-io fluid dscritio Two-io lasma Sigl-io (roto) lasma gyro-radius ffcts Faraday s law: two-io lasma charg utrality: h Magtic fild quatio x E x 1-0 h µ 0 t x E sigl-io lasma ( ) 0 1 t 0 h h µ x x 0 t 0 µ x x x µ 1-0 Hall trm Hall trm

20 20 0 ) ( t Cotiuity ad momtum quatios of rotos ad hais ( h, h ) Faraday s law. 0-1)P ( ) P ( P t γ Elctro rgy quatio h, with µ µ h h ) 2 (P ) ( m ) m P ( ) ( t - I x 1 / µ 0 h h x Th two-io Hall-MHD quatios ( ) 0 1 t 0 h h µ x x 2D hybrid simulatio of solar wid - comt itractio solar wid magtic fild hay io sourc: wakly outgassig comt (Wirta at 3 AU) Liato ad Saur, 1997 E

21 Comariso btw two-io fluid ad hybrid cod simulatios Itractio of th solar wid with a wak comt (Wirta at 3 AU) 3D hybrid cod simulatios Two-io fluid simulatios magtic fild solar wid hay io sourc M A 10, Q h s-1 agdoat ad Motschma, Saur t al., Plasma structurs for thr mass-loadig rgims hay-io dsity wak comt: Q<10 26 s -1 roto dsity icrasd. rat: Q s -1 comt lik G-S: Q s -1 Formatio of a roto caity Saur ad Dubii,

22 Two-fluid modlig of solar wid itractio with th Martia xoshric lasma A roto caity is formd. At th boudary saratig solar wid rotos from xoshric oxyg ios (IC Io Comositio oudary) th magtic fild ils u (MP) Saur ad Dubii, 1999 Comariso btw Phobos-2 obsratios ad two-fluid modlig (llitical orbit) Phobos-2 obsratios 2-fluid modlig S IC S IC 22

23 Comariso btw Phobos-2 obsratios ad two-fluid modlig (circular orbit) Phobos-2 obsratios S S IC 2-fluid modlig S IC S IC Hybrid simulatios: Formatio of a roto caity roto caity magtic fild IC solar wid hay io sourc Liato ad Saur,

24 3D hybrid simulatios of SW itractio with umagtizd lats Platary ios ar distributd or a shr, o iooshric rofils: Shimazu, 2001 rotos oxyg Imortat rsults: (1) Formatio of a IC (2) Multil shockstructur (3) Plasma acclratio at th flaks 3D hybrid simulatios of solar wid - Mars itractio (ößwttr, agdoat, Motschma - TU rauschwig K. Saur - MPA; 2004) S IC IC MP roto caity Mai sigaturs of itractio ar s. Locatio of S ad MP/IC ar i good agrmt with th obsratios. 24

25 Th Io Comositio oudary (IC) - a w ty of lasma boudary Shock > s soic oit < s soic oit < s hay-io lasma IC IC A shock is formd if th sursoic flow gos through th soic oit : s A IC is formd if th subsoic two-io flow bcoms acclratd ad gos through th gralizd soic oit : s (, h, h,β,...) Formatio of a roto caity i a subsoic flow hay-io cloud: h roto flow (M s 0.4) roto caity Saur t al.,

26 Plasma acclratio at th flaks of a imtrabl hay-io cloud hay-io cloud roto flow (M s 0.4) Th subsoic lasma flow (M s 0.4) is acclratd ad dflctd by th hay-io cloud i rgios whr its dsity is about Two-fluid modlig of SWhay io sourc itractio: 0 M s 4 solar wid Formatio of a roto caity hay-io sourc: qq m x(-r 2 /L 2 ) h h 26

27 Obsratio of shar boudaris i dusty lasmas udr micro-graity (Aarato t al., 2002) Argo lasma dust articls d3,4 µm dust articls d6,8 µm Obsratio of shar boudaris i dusty lasmas udr micro-graity dust oid Argo lasma Small articls Larg articls Itrfacs Tsytoich t al., x(mm)

28 Summary ad coclusio Th multi-fluid modl is abl to dscrib sstial lmts of solar wid itractio with o-magtizd bodis. Th trasitio from ry asymmtric lasma structurs at wak comts to th magtoshr of Mars with thr wll dlod lasma boudaris (S, IC/MP, IP) has b show. Th Io Comositio oudary (IC/MP) at comts ad Mars is a w ty of lasma boudary which is formd i mass-loadd lasmas. It rsults from th momtum coulig btw th two lasma oulatios at th gralizd soic oits. Summary ad coclusio Th rsults ha imlicatios to futur sac missios: ROSETTA I-situ masurmts ar a (wak) comt at ~ 3AU. MARS/VENUS EXPRESS Plasma ad utral gas masurmts with ASPERA-3. CASSINI Nw rsults about solar wid -Tita itractio. i Colombo Mrcury with its sodium atmoshr is a itrstig multi-io objct. 28

29 Summary ad coclusio Th work was do i th rojct Mars, Komt, kli Körr ~25 ublicatios i low costs: EU r aum...(cotacts to ISSI, CNRS, JPL) 29