[en] The Hubble Space Telescope (HST) data set obtained over two campaigns in 2007 is used to determine the long-term variability of the different components of Jupiter's auroras. Three regions on the planet's disc are defined: the main oval, the low-latitude auroras, and the high-latitude auroras. The UV auroral power emitted from these regions is extracted and compared to estimated solar wind conditions projected to Jupiter's orbit from Earth. In the first campaign the emitted power originated mainly from the main oval and the high-latitude regions, and in the second campaign the high-latitude and main oval auroras were dimmer and less variable, while the low-latitude region exhibited bright, patchy emission. We show that, apart from during specific enhancement events, the power emitted from the poleward auroras is generally uncorrelated with that of the main oval. The exception events are dawn storms and compression region enhancements. It is shown that the former events, typically associated with intense dawnside main oval auroras, also result in the brightening of the high-latitude auroras. The latter events associated with compression regions exhibit a particular auroral morphology; that is, where it is narrow and well defined, the main oval is bright and located ~1° poleward of its previous location, and elsewhere it is faint. Instead there is bright emission in the poleward region in the postnoon sector where distinct, bright, sometimes multiple arcs form.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Nichols, J. D.; University of Leicester, Leicester, UK > Department of Physics and Astronomy
Clarke, J. T.; Boston University, Boston, Massachusetts, USA > Center for Space Physics
Gérard, Jean-Claude ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Grodent, Denis ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Hansen, K. C.; Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan, USA > Department of Atmospheric
Language :
English
Title :
Variation of different components of Jupiter's auroral emission
Publication date :
01 June 2009
Journal title :
Journal of Geophysical Research. Space Physics
ISSN :
2169-9380
eISSN :
2169-9402
Publisher :
American Geophysical Union (AGU), Washington, United States - District of Columbia
Acton, C. H. (1996), Ancillary data services of NASA's Navigation and Ancillary Information Facility, Planet Space Sci., 44, 65-70.
Ballester, G. E., et al. (1996), Time-resolved observations of Jupiter's farultraviolet aurora, Science, 274, 409-412.
Bonfond, B., D. Grodent, J.-C.Gérard, A. Radioti, J. Saur, and S. Jacobsen (2008), UV Io footprint leading spot: A key feature for understanding the UV Io footprint multiplicity?, Geophys. Res. Lett., 35, L05107, doi:10.1029/2007GL032418. (Pubitemid 351675985)
Boudouridis, A., E. Zesta, L. R. Lyons, P. C. Anderson, and D. Lummerzheim (2003), Effect of solar wind pressure pulses on the size and strength of the auroral oval, J. Geophys. Res., 108(A4), 8012, doi:10.1029/2002JA009373.
Bunce, E. J., S. W. H. Cowley, and T. K. Yeoman (2004), Jovian cusp processes: Implications for the polar aurora, J. Geophys. Res., 109, A09S13, doi:10.1029/2003JA010280.
Clarke, J. T., H. W. Moos, S. K. Atreya, and A. L. Lane (1980), Observations from earth orbit and variability of the polar aurora on Jupiter, Astrophys. J., 241, L179-L182, doi:10.1086/183386.
Clarke, J. T., L. Ben Jaffel, and J.-C. Gérard (1998), Hubble Space Telescope imaging of Jupiter's UV aurora during the Galileo orbiter mission, J. Geophys. Res., 103, 20,217-20,236, doi:10.1029/98JE01130.
Clarke, J. T., et al. (2002), Ultraviolet emissions from the magnetic footprints of Io, Ganymede and Europa on Jupiter, Nature, 415, 997-1000.
Clarke, J. T., D. Grodent, S. W. H. Cowley, E. J. Bunce, P. Zarka, J. E. P. Connerney, and T. Satoh (2004), Jupiter's aurora, in Jupiter. The Planet, Satellites and Magnetosphere, edited by F. Bagenal, T. E. Dowling, and W. B. McKinnon, pp. 639-670, Cambridge. Univ. Press, Cambridge, U. K.
Clarke, J. T., et al. (2009), The response of Jupiter's and Saturn's auroral activity to the solar wind, J. Geophys. Res., 114, A05210, doi:10.1029/2008JA013694.
Cowley, S. W. H., and E. J. Bunce (2001), Origin of the main auroral oval in Jupiter's coupled magnetosphere-ionosphere system, Planet. Space Sci., 49, 1067-1088.
Cowley, S. W. H., and E. J. Bunce (2003a), Modulation of Jupiter's main auroral oval emissions by solar wind induced expansions and compressions of the magnetosphere, Planet. Space Sci., 51, 57-79.
Cowley, S. W. H., and E. J. Bunce (2003b), Modulation of Jovian middle magnetosphere currents and auroral precipitation by solar wind-induced compressions and expansions ofthemagnetosphere: Initial response and steady state, Planet. Space Sci., 51, 31-56.
Cowley, S. W. H., I.I. Alexeev, E. S. Belenkaya, E. J. Bunce, C.E. Cottis, V. V. Kalegaev, J. D. Nichols, R. Prangé, and F. J. Wilson (2005), A simple axisymmetric model of magnetosphere-ionosphere coupling currents in Jupiter's polar ionosphere, J.Geophys. Res., 110, A11209, doi:10.1029/2005JA011237.
Cowley, S. W. H., J. D. Nichols, and D. J. Andrews (2007), Modulation of Jupiter's plasma flow, polar currents, and auroral precipitation by solar wind-induced compressions and expansions of the magnetosphere: a simple theoretical model, Ann. Geophys., 25, 1433-1463.
Elliott, H. A. (2007), New Horizons SWAP solar wind measurements at Jupiter encounter, paper presented at the Magnetospheres of the Outer Planets Conference, Soumwest Res. Inst., San Antonio, Tex., 25-29 June.
Elsner, R. F., et al. (2005), Simultaneous Chandra X ray, Hubble Space Telescope ultraviolet, and Ulysses radio observations of Jupiter's aurora, J. Geophys. Res., 110, A01207, doi:10.1029/2004JA010717.
Gérard, J.-C., J. Gustin, D. Grodent, P. Delamere, and J. T. Clarke (2002), Excitation oftheFUV Io tail on Jupiter: Characterization of the electron precipitation, J. Geophys. Res., 107(A11), 1394, doi:10.1029/ 2002JA009410.
Gérard, J.-C., A. Saglam, D. Grodent, and J. T. Clarke (2006), Morphology oftheultraviolet Io footprint emission and its control by Io's location, J. Geophys. Res., III, A04202, doi:10.1029/2005JA011327.
Gong, B. (2005), Variations of Jovian aurora induced by changes in solar wind dynamic pressure, Ph.D. thesis, Rice Univ., Houston, Tex.
Grodent, D., J. T. Clarke, J. Kim, J. H. Waite, and S. W. H. Cowley (2003a), Jupiter's main auroral oval observed with HST-STIS, J. Geophys. Res., 108(A11), 1389, doi:10.1029/2003JA009921.
Grodent, D., J. T. Clarke, J. H. Waite, S. W. H. Cowley, J.-C. Gérard, and J. Kim (2003b), Jupiter's polar auroral emissions, J. Geophys. Res., 108(A10), 1366, doi:10.1029/2003JA010017.
Grodent, D., B. Bonfond, J.-C. Gérard, A. Radioti, J. Gustin, J. T. Clarke, J. Nichols, and J. E. P. Connerney (2008a), Auroral evidence of a localized magnetic anomaly in Jupiter's northern hemisphere, J. Geophys. Res., 113, A09201, doi:10.1029/2008JA013185.
Grodent, D., J.-C. Gérard, A. Radioti, B. Bonfond, and A. Saglam (2008b), Jupiter's changing auroral location, J. Geophys. Res., 113, A01206, doi:10.1029/2007JA012601.
Gurnett, D. A., et al. (2002), Control of Jupiter's radio emission and aurorae by the solar wind, Nature, 415, 985-987.
Gustin, J., S. W. H. Cowley, J.-C. Gérard, G. R. Gladstone, D. Grodent, and J. T. Clarke (2006), Characteristics of Jovian morning bright FUV aurora from Hubble Space Telescope/Space Telescope Imaging Spectrograph imaging and spectral observations, J.Geophys. Res., III, A09220, doi:10.1029/ 2006JA011730.
Hanlon, P. G., M. K. Dougherty, N. Krupp, K. C. Hansen, F. J. Crary, D. T. Young, and G. Tóth (2004), Dual spacecraft observations of a compression event within the Jovian magnetosphere: Signatures of externally triggered supercorotation?, J. Geophys. Res., 109, A09S09, doi:10.1029/ 2003JA010116.
Hill, T. W. (2001), The Jovian auroral oval, J. Geophys. Res., 106, 81018108, doi:10.1029/2000JA000302.
Khurana, K. K. (2001), Influence of solar wind on Jupiter's magnetosphere deduced from currents in the equatorial plane, J. Geophys. Res., 106, 25,999-26,016, doi:10.1029/2000JA000352.
Nichols, J. D., and S. W. H. Cowley (2004), Magnetosphere-ionosphere coupling currents in Jupiter's middle magnetosphere: Effect of precipitation-induced enhancement of the ionospheric Pedersen conductivity, Ann. Geophys., 22, 1799-1827.
Nichols, J. D., S. W. H. Cowley, and D. J. McComas (2006), Magnetopause reconnection rate estimates for Jupiter's magnetosphere based on interplanetary measurements at ∼5AU, Ann. Geophys., 24, 393-406.
Nichols, J. D., E. J. Bunce, J. T. Clarke, S. W. H. Cowley, J.-.C. Gérard, D. Grodent, and W. R. Pryor (2007), Response of Jupiter's UV auroras to interplanetary conditions as observed bytheHubble Space Telescope during the Cassini flyby campaign, J.Geophys. Res., 112, A02203, doi:10.1029/2006JA012005.
Pallier, L., and R. Prangé (2001), More about the structure of the high latitude Jovian aurorae, Planet. Space Sci., 49, 1159-1173.
Prangé, R., G. Chagnon, M. G. Kivelson, T. A. Livengood, and W. Kurth (2001), Temporal monitoring of Jupiter's auroral activity with IUE during the Galileo mission. Implications for magnetospheric processes, Planet. Space Sci., 49, 405-415. (Pubitemid 33648524)
Pryor, W. R., et al. (2005), Cassini UVIS observations of Jupiter's auroral variability, Icarus, 178, 312-326, doi:10.1016/j.icarus.2005.05.021. (Pubitemid 41548992)
Radioti, A., D. Grodent, J.-C. Gérard, B. Bonfond, and J. T. Clarke (2008), Auroral polar dawn spots: Signatures of internally driven reconnection processes at Jupiter's magnetotail, Geophys. Res. Lett., 35, L03104, doi:10.1029/2007GL032460.
Serio, A. W., and J. T. Clarke (2008), The variation of Io's auroral footprint brightness wim the location of Io in the plasma torus, Icarus, 197, 368374, doi:10.1016/j.icarus.2008.03.026.
Soumwood, D. J., and M. G. Kivelson (2001), A new perspective concerning the influence of the solar wind on the Jovian magnetosphere, J. Geophys. Res., 106, 6123-6130, doi:10.1029/2000JA000236.
Tsurutani, B. T., and X. Y. Zhou (2003), Interplanetary shock triggering of substorms: Wind and polar, Adv. Space Res., 31(4), 1063-1067, doi:10.1016/S0273-1177(02)00796-2.
Vasavada, A. R., A. H. Bouchez, A. P. Ingersoll, B. Little, C. D. Anger, and the Galileo SSI team (1999), Jupiter's visible aurora and Io footprint, J. Geophys. Res., 104, 27,133-27,142.
Vincent, M. B., et al. (2000), Mapping Jupiter's latitudinal bands and Great Red Spot using HST/WFPC2 far-ultraviolet imaging, Icarus, 143, 189204, doi:10.1006/icar.1999.6232.
Waite, J. H., et al. (2001), An auroral flare at Jupiter, Nature, 410, 787-789.
Zieger, B., and K. C.Hansen (2008), Statistical validation of a solar wind propagation model from 1 to 10 AU, J. Geophys. Res., 113, A08107, doi:10.1029/2008JA013046.
