a subalfvenic plasma flow past the magnetized obstacle: ganymede magnetosphere scobeltsyn institute...

A subalfvenic plasma flow past the magnetized obstacle: Ganymede magnetosphereScobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Leninskie Gory, 119992, Moscow, Russia [email protected] I. Alexeev and Elena S. Belenkaya

Content Jupiter magnetosphere global structure and magnetic field at Ganymedes orbit

Ganymede aurora spot at Jupiter and aurora at Ganymede

Ganymede orbit placed near to (1) Jupiter magnetosphere Alfenic radius, (2) inner edge of the Jovian current disk, (3) equatorial projection of the main oval

Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*

Space Research Institute, 7 March 2013, 12:00 12:20

Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*2013 February 15Astronomy Picture of the DayShadows Across Jupiter Image Credit &Copyright:Damian Peach


Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*Paraboloid model full sizeNear Ganymede magnetosphere Alexeev, Belenkaya, AG, [2005]


Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*Paraboloid model of the Jovian magnetosphereModel components In a Jovian solar-magnetospheric coordinate system: Bm(t) = Bd() - planetary field vector+ BMD(,BDc,RD1,RD2) - field from equatorial current disc + Bsd (,R1) - from currents shielding planetary field+ BMD(,BDc, R1,RD1,RD2) - field from currents shielding current disc field+ BTS(,,R2,Bt) - from cross-tail + closure magnetopause currents + b(kJ,BIMF) - fraction of the IMF penetrating the magnetosphere

Time-dependent model parameters

magnetic dipole tilt angleR1 subsolar MP distanceRD2 and RD1 radial distances of the inner and outer edges of the current discR2 radial distance of the inner edge of the tail current sheetBt/(1+2 R2/ R1)1/2 tail field strength at the inner edge of the tail current sheetBDC current disc field strength at the outer edge of the current discBIMF IMF vectorkJ coefficient of the IMF penetrationAlexeev, Belenkaya, AG[2005]


Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*The transition from dipole like to stretched tail-like field lines in Jupiter magnetosphere. R1RD1RD2RD1R2 =0 Bt=3 nT BDC=3 nT

R1 =92.8 RJR2 =85.4 RJRD1 =84.4 RJRD2 =16.4 RJ


Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*The transition from dipole like to stretched tail-like field lines. Nearest Earth tail edge (e.g. Lui et al., 1992). The carton is based on data by AMPTE CCE Magnetic Field Experiment


Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*Ulysses the jovian magnetospheric magnetic fieldMeasured by Ulysses the magnetic field dependent on the radial distance r (Cowley et al., 1996) is marked by solid curve. For comparison there are also shown magnetic field strength calculated by present model (heavy curve).

Alexeev and Belenkaya, AG, [2005] Equatorial current disk


Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*Relative intensity versus pitch angle versus time and position for 15- to 29-keV electron data as generated and reported by Tomas et al. [2004a, 2004b] using data from the Galileo EPD instrument


Energetic ion spectra and plasma beta=1 at Ganymede orbitGanymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*Mauk et al. [2002]


Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*Satellite Footprints Seen in Jupiter AuroraThis ultraviolet image of Jupiter was taken with the Hubble Space Telescope Imaging Spectrograph (STIS) on November 26, 1998. John Clarke, BU, USA. Ganymede's auroral footprint. near the center,


Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*Unipolar jovian generator Schematic of the relationship between observed equatorial electron field-aligned enhancements reported by Tomas et al. [2004a, 2004b] and the circuit of electric currents that connects Jupiters middle magnetosphere to the auroral ionosphere. The auroral circuit figure is based on concepts of Hill [1979] and Vasyliunas [1983] as replotted by Mauk et al. [2002]. It is understood that the shape of the field lines in the actual Jovian system are substantially stretched away from the dipolar configuration. Landay and Lifshitz, 1959Mauk et al. [2002].


Ganymede/plasma parametersBo, jovian magnetic field, 64 nTne, 5 elns cm3< Z >, eq. av. (lobe) ion charge 1.3 < A >, eq. av. (lobe) ion mass in mp 14 ni, ion no. density 4 ions/cm3m, ion mass density 54 amu/cm3kTi, equator ion temperature 60 eVkTe, electron temperature 300 eV pi,th, pressure thermal 0.04 nPapi,en (20 keV 100 MeV ions) 3.6 nPa pe (both cold and hot electrons) 0.2 nPap(nPa), eq. (max) total pressure 3.8 nPa

vcr, local corotation velocity 187 km/s vs, satellite orbit velocity 11 km/s v, plasma azimuthal vel. 150 km/su, relative velocity (range), 139 km/s vA, eq. Alfven speed 190 km/s cs, eq. sound speed 280 km/s B2o/2o, eq. (lobe) magnetic pressure 1.6 nPau2, eq. av. ram pressure 1.7 nPau2, lobe ram pressure 0.08 nPa

Bs, maximum Ganymede surface field 1500 nTA= (ovA)1, Alfven cond. eq. 4.2 S P, av. ionosph. Pedersen cond 2 S H, av. ionosph. Hall cond 0.1 SM/mi, ions per s added locally to flow 6x1026 s1

fpe, av. electron plasma freq. 20 kHzfpi, av. plasma freq. mass mi ion 140 Hzfce, eq. (lobe) electron cyclotron freq. 1.8 kHzfci, eq. (lobe) cyclotron freq. mass mi ion 0.09 Hzg,th thermal ions gyroradii eq. (lobe) 36 kmg,pu pickup ions gyroradii eq. (lobe) 200 km

MA = u/vA equator (range) 0.73Ms = u/cs(range) Mf = u/( v2A + c2s)1/2 (range) 0.5v /vcr 0.8 A (degrees) =tan1(u/vA) 36 = p / (B2/2o) (lobe) 2.4P (av)g/A (eq) 0.5M /iur2s(range) 5-500Bsurf / Bbg(range) 13-23,pgu/rs(range) 0.01-0.08Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*Kivelson, et al. (2004), Magnetospheric interactions with satellites, in Jupiter: The Planet, Satellites and Magnetosphere, Cambridge Univ. Press, Cambridge, U. K.


Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*Inductive interaction of conducting bodies with amagnetized plasma, A. V. Gurevich, A. L. Krylov, and E. N. Fedorov, Zh. Eksp. Teor. Fi., 75, 2132-2140 (1978) VA

Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*Jia et al., JGR, 2009


Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*Imp=2 RssBmp/0=1 MAI=A 6RGV flow BJ

I = DVB/0VA, Belcher [1987]

I= MA 6RG BJ/0=1.14 MAJia et al., JGR, 2008


Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*Figure 1. Raw HST image (zoom) of Jupiters northern auroral region displaying the ultravioletfootprint of Ganymede in the anomaly region. The image was obtained with HST/ACS/SBC with the F125LP filter on 2 March 2007 during the GO-10862 HST campaign. The central meridian longitude is 145 (S3), and the exposure time is 100 s.

Controversy Grodent, D., B. Bonfond, A. Radioti, J.-C. Gerard, X. Jia, J. D. Nichols, and J. T. Clarke (2009), Auroral footprint of Ganymede, J. Geophys. Res., 114, A07212, doi:10.1029/2009JA014289


Hubble Space Telescope images shown auroral emission from electron excited atomic oxygen. Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*Controversy Mellisa A McGrat et al, JGR, in press 2013 doi: 10.1002/jgra.50122 Line at 1356 Open-closed field line boundaryThe thermal Jovian plasma at Ganymede can produce a maximum of only ~10-40 R, Max brightness are 200 R 400 R 300 R intensity can produce by 75-300 eV


The emitted power of Ganymedes auroral foot-print as a function of Ganymedes orbital longi-tude and, consistently, as a function of Ganymedes latitude in Jupiters plasma sheet.Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*Controversy Grodent et al, JGR, 2009Ganymedes auroral footprint 400 kV2 A = 800 GW Emitted power 2 GW ~0.25%


ConclusionsGanymedes orbit is mostly interesting region of the Jupiters magnetosphere.Magnetometer and energetic particle detector with energy 1 keV 1 Mev data will bring a high scientific output.Steady magnetic reconnection and particle acceleration can be studiedAurora phenomena can be studied by UV imagerGanymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*


Thank you!!!Ganymede Lander, GLCW_6_06, Moscow Space Research Institute, 7 March 2013, 12:00 12:20*


Explanation:Two dark shadows loom across the banded and mottledcloud tops of Jupiterin this sharp telescopic view. In fact, captured on January 3rd, about a month after the ruling gas giant appeared at opposition inplanet Earth's sky, the scene includes the shadow casters. Visible inremarkabledetail at the left are the largeGalilean moonsGanymede (top) and Io. With the two moon shadows still in transit, Jupiter'srapid rotationhas almost carried its famousGreat Red Spot(GRS) around the planet's limb from the right. The pale GRS was preceded by the smaller but similar huedOval BA, dubbed Red Spot Jr., near top center. North is down in theinvertedimage.

*Kivelson, M. G., F. Bagenal, W. S. Kurth, F. M. Neubauger, C. Paranicas, and J. Saur (2004), Magnetospheric interactions with satellites, in Jupiter: The Planet, Satellites and Magnetosphere, edited by F. Bagenal, T. E. Dowling, and W.B. McKinnon,pp.513 536, Cambridge Univ. Press, Cambridge, U. K.

* Figure 4. (a) Flows and the projection of field lines (white solid lines) in the XZ plane at Y = 0. Colorrepresents the Vx contours, and unit flow vectors in yellow show the flow direction. A theoreticalprediction of the Alfven characteristics (orange dashed lines) is shown for reference. The projection of theionospheric flow is also shown as color contours on a circular disk of r = 1.08 RG in the center. (b) Azoomed-in view of the light area in Figure 4a. Flow streamlines are superimposed on color contours ofVx. Note that the color bar differs from that in Figures 4a and 4b in order to illustrate the relatively weakflow within the magnetosphere. (c) Same as Figure 4a but in the YZ plane at X = 0. (d) Field-alignedcurrent density along with unit flow vectors shown on a sphere of radius r = 1.08 RG.*Figure 7. (a) Color contours of the current density (Jy) in the ^Y direction plotted in the XZ plane at Y =0. The projection of magnetic field lines in this plane is superposed as green lines with arrowheadsrepresenting the field orientation. (b) Same as Figure 7a but for the field-aligned current density (Jpar) inthe YZ plane. Flow is into the plane. (c) A global view of the current flowlines in the magnetospherefrom the upstream flank side. The axes are labeled in units of Ganymedes radii RG.

*Figure 2. Ganymede auroral emission from atomic oxygen illustrating the different morphologies on the different hemispheres of the satellite. The magnetospheric plasma flow is into the page for the trailing hemisphere, out of the page for the leading hemisphere, and approximately from right to left for the Jupiter-facing hemisphere. The black and white dashed line in each image represents the 0 (2003 and 2007), 90 (2000), or 270 (1998) deg W longitude meridian.

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a subalfvenic plasma flow past the magnetized obstacle: ganymede magnetosphere scobeltsyn institute...

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