[en] We report the presence of polar spots located in the dawn auroral region, based on the HST ACS 2007 campaign. We study the location of these features in the equatorial plane as well as their time scales and periodicities, based on a comprehensive series of images taken between February 21 and June 11, 2007. It is shown that the majority of polar dawn spots magnetically map to the dawn sector. Additionally, they occur quasi-periodically every 2-3 days, a periodicity observed for the first time in auroral features. Because of their mapped location and their periodic cycle, we interpret the polar dawn spots as signatures of internally driven magnetic reconnection in the Jovian magnetotail.
Disciplines :
Physical, chemical, mathematical & earth Sciences: Multidisciplinary, general & others
Author, co-author :
Radioti, Aikaterini ; 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)
Gérard, Jean-Claude ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Bonfond, Bertrand ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Clarke, J. T.; Center for Space Physics, Boston University, Boston, USA
Language :
English
Title :
Auroral polar dawn spots: Signatures of internally driven reconnection processes at Jupiter's magnetotail
Publication date :
07 February 2008
Journal title :
Geophysical Research Letters
ISSN :
0094-8276
eISSN :
1944-8007
Publisher :
American Geophysical Union, Washington, United States - District of Columbia
Baker, D. N., T. I. Pulkkinen, V. Angelopoulos, W. Baumjohann, and R L. McPherron (1996), Neutral line model of substorms: Past results and present view, J. Geophys. Res., 101, 12,975-13,010.
Bonfond, B. (2007), The Io footprint: Analysis of Hubble Space Telescope observations of Jupiter's aurorae, M. S. thesis, Univ of Liege, Liege, Belgium.
Clarke, J. T., et al. (1998), Hubble Space Telescope imaging of Jupiter's UV aurora during the Galileo orbiter mission, J. Geophys. Res., 103, 20,217-20,236.
Connerney, J. E. P., M. H. Acuña, N. F. Ness, and T. Satoh (1998), New models of Jupiter's magnetic field constrained by the Io flux tube footprint, J. Geophys. Res., 103, 11,929-11,939.
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., E. J. Bunce, T. S. Stallard, and S. Miller (2003), Jupiter's polar ionospheric flows: Theoretical interpretation, Geophys. Res. Lett., 30(5), 1220, doi:10.1029/2002GL016030.
Grodent, D., J. T. Clarke, J. Kim, J. H. Waite Jr., 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 Jr., 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., J.-C. Gérard, J. T. Clarke, G. R. Gladstone, and J. H. Waite Jr. (2004), A possible auroral signature of a magnetotail reconnection process on Jupiter, J. Geophys. Res., 109, A05201, doi:10.1029/2003JA010341.
Hill, T. W. (2001), The Jovian auroral oval, J. Geophys. Res., 106, 8101-8107.
Kronberg, E. A., J. Woch, N. Krupp, A. Lagg, K. K. Khurana, and K.-H. Glassmeier (2005), Mass release at Jupiter: Substorm-like processes in the Jovian magnetotail, J. Geophys. Res., 110, A03211, doi:10.1029/2004JA010777.
Kronberg, E. A., K.-H. Glassmeier, J. Woch, N. Krupp, A. Lagg, and M. K. Dougherty (2007), A possible intrinsic mechanism for the quasi-periodic dynamics of the Jovian magnetosphere, J. Geophys. Res., 112, A05203, doi:10.1029/2006JA011994.
Krupp, N., J. Woch, A. Lagg, B. Wilken, S. Livi, and D. J. Williams (1998), Energetic particle bursts in the predawn Jovian magnetotail, Geophys. Res. Lett., 25, 1249-1252.
Louarn, P., A. Roux, S. Perraut, W. Kurth, and D. Gurnett (1998), A study of the large-scale dynamics of the Jovian magnetosphere using the Galileo plasma wave experiment, Geophys. Res. Lett., 25, 2905-2908.
Russell, C. T., K. K. Khurana, D. E. Huddleston, and M. G. Kivelson (1998), Localized reconnection in the near Jovian magnetotail, Science, 280, 1061-1064.
Russell, C. T., K. K. Khurana, M. G. Kivelson, and D. E. Huddleston (2000), Substorms at Jupiter: Galileo observations of transient reconnection in the near tail, Adv. Space Sci., 26(10), 1499-1504.
Vasyliunas, V. M. (1983), Plasma distribution and flow, in Physics of the Jovian Magnetosphere, edited by A. Dessler, pp. 395-453, Cambridge Univ. Press, New York.
Woch, J., N. Krupp, A. Lagg, B. Wilken, S. Livi, and D. J. Williams (1998), Quasi periodic modulations of the Jovian magnetotail, Geophys. Res. Lett., 25, 1253-1256.
Woch, J., et al. (1999), Plasma sheet dynamics in the Jovian magnetotail: Signatures for substorm-like processes?, J. Geophys. Res., 26,2137-2140.
Woch, J., N. Krupp, and A. Lagg (2002), Particle bursts in the Jovian magnetosphere: Evidence for a near-Jupiter neutral line, Geophys. Res. Lett., 29(7), 1138, doi:10.1029/2001GL014080.