IMAGE satellite; energy input; magnetospheric processes; substorm
Abstract :
[en] Substorm energetics has been shown to have two components, the "loading-unloading'' component releasing energy previously stored in the tail and the "directly driven'' component dissipating simultaneously fed solar wind energy. Previous studies disagree about the relative importance of each process. The SI12 spectral imager onboard the IMAGE satellite provides images of the Doppler-shifted Lyman alpha auroral emission at 121.8 nm every 2 min. It has been used to determine the auroral intensity during substorms, which may be compared to the solar wind characteristics and interplanetary magnetic field components before and/or after substorm onsets. In this study, we analyze 256 substorms between June 2000 and December 2002, which satisfy criteria relative to the viewing conditions. We compare the mean nightside intensity during the expansion phase with the magnetic open flux, the epsilon parameter, and other coupling functions (used as proxies of transfer of solar wind energy to the magnetosphere) integrated over the growth phase or the expansion phase. The mean auroral intensity during the expansion phase correlates well with coupling functions integrated over the growth phase. We also find that the correlation between the auroral precipitation during the expansion phase and the coupling functions integrated over the expansion phase is lower but still significant. This implies that, even though both mechanisms contribute to the energy precipitated during substorms, the loading-unloading process is statistically dominant.
Gérard, Jean-Claude ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Coumans, Valérie ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Hubert, Benoît ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Meurant, M.
Language :
English
Title :
Contributions of the driven process and the loading-unloading process during substorms: A study based on the IMAGE-SI12 imager
Publication date :
2009
Journal title :
Journal of Geophysical Research
ISSN :
0148-0227
eISSN :
2156-2202
Publisher :
American Geophysical Union (AGU), Washington, United States - Washington
Akasofu, S.-I. (1964), The development of the auroral substorm, Planet. Space Sci., 12, 273, doi:10.1016/0032.
Akasofu, S.-I. (1981), Energy coupling between the solar wind and the magnetosphere, Space Sci. Rev., 28, 121, doi:10.1007/BF00218810.
Arnoldy, R. L. (1971), Signature in the interplanetary medium for substorms, J. Geophys. Res., 76, 5189, doi:10.1029/JA076i022p05189.
Axford, W. I., and C. O. Hines (1961), A unifying theory of high-latitude geophysical phenomena and geomagnetic storms, Can. J. Phys., 39, 1433.
Baker, D. N., A. J. Klimas, D. Vassiliadis, T. I. Pulkkinen, and R. L. McPherron (1997), Reexamination of driven and unloading aspects of magnetospheric substorms, J. Geophys. Res., 102, 7169, doi.10.1029/96JA02627.
Bargatze, L. F., D. N. Baker, R. L. McPherron, and E. W. Hones Jr. (1985), Magnetospheric impulse response for many levels of geomagnetic activity, J. Geophys. Res., 90, 6387, doi:10.1029/JA090iA07p06387.
Coumans, V, J.-C. Gérard, B. Hubert, and M. Meurant (2006), Global auroral proton precipitation observed by IMAGE-FUV: Noon and midnight brightness dependence on solar wind characteristics and IMF orientation, J. Geophys. Res., 111, A05210, doi:10.1029/2005JA011317.
Coumans, V., C. Blockx, J.-C. Gérard, B. Hubert, and M. Connors (2007), Global morphology of substorm growth phases observed by the IMAGE-SI12 imager, J. Geophys. Res., 112, A11211, doi:10.1029/2007JA012329.
Cowley, S. W. H., and M. Lockwood (1992), Excitation and decay of solar wind-driven flows in the magnetosphere-ionosphere system, Ann. Geophys., 10, 103.
Dungey, J. W. (1961), Interplanetary field and the auroral zones, Phys. Rev. Lett., 6, 47, doi:10.1103/PhysRevLett.6.47.
Frey, H. U., S. B. Mende, T. J. Immel, J. C. Gérard, B. Hubert, S. Habraken, J. Spann, G. R. Gladstone, D. V. Bisikalo, and V. I. Shematovich (2003), Summary of quantitative interpretation of IMAGE far ultraviolet auroral data, Space Sci. Rev., 109, 255, doi: 10.1O23/B:SPAC.OOOOOO7521.39348.a5.
Frey, H. U., S. B. Mende, V. Angelopoulos, and E. F. Donovan (2004), Substorm onset observations by IMAGE-FUV, J. Geophys. Res., 109, A10304, doi: 10.1029/2004JA010607.
Gérard, J.-C, B. Hubert, D. V. Bisikalo, and V. I. Shematovich (2000), A model of the Lyman-α line profile in the proton aurora, J. Geophys. Res., 105, 15, 795, doi: 10.1029/1999JA002002.
Gérard, J.-C, B. Hubert, M. Meurant, V. I. Shematovich, D. V. Bisikalo, H. Frey, S. Mende, G. R. Gladstone, and C. W. Carlson (2001), Observation of the proton aurora with IMAGE FUV imager and simultaneous ion flux in situ measurements, J. Geophys. Res., 106, 28, 939, doi:10.1029/2001JA900119.
Gonzalez, W. D., and F. S. Mozer (1974), A quantitative model for the potential resulting from reconnection with an arbitrary interplanetary magnetic field, J. Geophys. Res., 79, 4186, doi:10.1029/JA079i028p04186.
Grocott, A., S. W. H. Cowley, J. B. Sigwarth, J. F. Watermann, and T. K. Yeoman (2002), Excitation of twin-vortex flow in the nightside high-latitude ionosphere during an isolated substorm, Ann. Geophys., 20, 1577.
Hubert, B., S. E. Milan, A. Grocott, C. Blockx, S. W. H. Cowley, and J.-C. Gérard (2006), Dayside and nightside reconnection rates inferred from IMAGE FUV and Super Dual Auroral Radar Network data, J. Geophys. Res., 111, A03217, doi:10.1029/2005JA011140.
Ieda, A., S. Machida, T. Mukai, Y. Saito, T. Yamamoto, A. Nishida, T. Terasawa, and S. Kokubun (1998), Statistical analysis of the plasmoid evolution with Geotail observations, J. Geophys. Res., 103, 4453, doi:10.1029/97JA03240.
Knipp, D. J., et al. (1998), An overview of the early November 1993 geomagnetic storm, J. Geophys. Res., 103, 26, 197, doi:10.1029/98JA00762.
Liou, K., P. T. Newell, C.-I. Meng, M. Brittnacher, and G. Parks (1998), Characteristics of the solar wind controlled auroral emissions, J. Geophys. Res., 103, 17, 543, doi:10.1029/98JA01388.
Lu, G., et al. (1998), Global energy deposition during the January 1997 magnetic cloud event, J. Geophys. Res., 103, ll, 685, doi:10.1029/98JA00897.
McComas, D. J., S. J. Bame, P. Barker, W. C. Feldman, J. L. Phillips, P. Riley, and J. W. Griffee (1998), Solar Wind Electron Proton Alpha Monitor (SWEPAM) for the Advanced Composition Explorer, Space Sci. Rev., 86, 563, doi:10.1023/A:1005040232597.
McPherron, R. L. (1970), Growth phase of magnetospheric substorms, J. Geophys. Res., 75, 5592, doi:10.1029/JA075i028p05592.
Mende, S. B., et al. (2000a), Far ultraviolet imaging from the IMAGE spacecraft. 1. System design, Space Sci. Rev., 91, 243, doi:10.1023/A:1005271728567.
Mende, S. B., et al. (2000b), Far ultraviolet imaging from the IMAGE spacecraft. 2. Wideband FUV imaging, Space Sci. Rev., 91, 271, doi: 10.1023/A:1005227915363.
Milan, S. E. (2004), A simple model of the flux content of the distant magnetotail, J. Geophys. Res., 109, A07210, doi: 10.1029/2004JA010397.
Milan, S. E., M. Lester, S. W. H. Cowley, K. Oksavik, M. Brittnacher, R. A. Greenwald, G. Sofko, and J.-P. Villain (2003), Variations in the polar cap area during two substorm cycles, Ann. Geophys., 21, 1121.
Milan, S. E., S. W. H. Cowley, M. Lester, D. M. Wright, J. A. Slavin, M. Fillingim, C. W. Carlson, and H. J. Singer (2004), Response of the magnetotail to changes in the open flux content of the magnetosphere, J. Geophys. Res., 109, A04220, doi:10.1029/2003JA010350.
Milan, S. E., G. Provan, and B. Hubert (2007), Magnetic flux transport in the Dungey cycle: A survey of dayside and nightside reconnection rates, J. Geophys. Res., 112, A01209, doi:10.1029/2006JA011642.
Perreault, P., and S.-I. Akasofu (1978), A study of geomagnetic storms, Geophys. J. R. Astron. Soc, 54, 547.
Pulkkinen, T. I., M. Palmroth, E. I. Tanskanen, P. Janhunen, H. E. J. Koskinen, and T. V. Laitinen (2006), New interpretation of magnetospheric energy circulation, Geophys. Res. Lett., 33, L07101, doi: 10.1029/2005GL025457.
Rostoker, G., S.-I. Akasofu, W. Baumjohann, Y. Kamide, and R. L. McPherron (1987), The roles of direct input of energy from the solar wind and unloading of stored magnetotail energy in driving magneto-spheric substorms, Space Sci. Rev., 46, 93.
Shukhtina, M. A., N. P. Dmitrieva, N. G. Popova, V. A. Sergeev, A. G. Yahnin, and I. V. Despirak (2005), Observational evidence of the loading-unloading substorm scheme, Geophys. Res. Lett., 32, L17107, doi: 10.1029/2005GL023779.
Siscoe, G. L., and T. S. Huang (1985), Polar cap inflation and deflation, J. Geophys. Res., 90, 543, doi:10.1029/JA090iA01p00543.
Smith, C. W., J. L'Heureux, N. F. Ness, M. H. Acuna, L. F. Burlaga, and J. Scheifele (1998), The ACE magnetic fields experiments, Space Sci. Rev, 86, 613, doi:10.1023/A:1005092216668.
Strickland, D. J., R. E. Daniell Jr., J. R. Jasperse, and B. Basu (1993), Transport-theoretic model for the electron-proton-hydrogen atom aurora: 2. Model results, J. Geophys. Res., 98, 21, 533, doi:10.1029/93JA01645.
Tsurutani, B. T, J. A. Slavin, Y. Kamide, R. D. Zwickl, J. H. King, and C. T. Russell (1985), Coupling between the solar wind and the magneto-sphere: CDAW 6, J. Geophys. Res., 90, 1191, doi: 10.1029/JA090iA02p01191.
Vasyliunas, V. M., J. R. Kan, G. L. Siscoe, and S.-I. Akasofu (1982), Scaling relations governing magnetospheric energy transfer, Planet. Space Sci., 30, 359, doi: 10.1016/0032.
Weimer, D. R., D. M. Ober, N. C. Maynard, W. J. Burke, M. R. Collier, D. J. McComas, N. F. Ness, and C. W. Smith (2002), Variable time delays in the propagation of the interplanetary magnetic field, J. Geophys. Res., 107(A8), 1210, doi:10.1029/2001JA009102.
Weimer, D. R., D. M. Ober, N. C. Maynard, M. R. Collier, D. J. McComas, N. F. Ness, C. W. Smith, and J. Watermann (2003), Predicting interplanetary magnetic field (IMF) propagation delay times using the minimum variance technique, J. Geophys. Res., 108(A1), 1026, doi:10.1029/2002JA009405. (Correction, J. Geophys. Res., 109, doi:10.1029/2004JA010961, 2004.)
Wygant, J. R., R. B. Torbert, and F. S. Mozer (1983), Comparison of S3-3 polar cap potential drops with the interplanetary magnetic field and models of magnetopause reconnection, J. Geophys. Res., 88, 5727, doi: 10.1029/JA088iA07p05727.