Badman, S.V. and Bonfond, B. and Fujimoto, M. and Gray, Becky and Kasaba, Y. and Kasahara, S. and Kimura, T. and Melin, H. and Nichols, J.D. and Steffl, A.J. and Tao, C. and Tsuchiya, F. and Yamazaki, A. and Yoneda, M. and Yoshikawa, I. and Yoshioka, K. (2016) Weakening of Jupiter's main auroral emission during January 2014. Geophysical Research Letters, 43 (3). pp. 988-997. ISSN 0094-8276
Badman_et_al_2016_Geophysical_Research_Letters.pdf - Published Version
Available under License Creative Commons Attribution.
Download (1MB)
Jupiter_aurora_weakening_newtex.pdf - Accepted Version
Available under License Creative Commons Attribution-NonCommercial.
Download (1MB)
Abstract
In January 2014 Jupiter's FUV main auroral oval decreased its emitted power by 70% and shifted equatorward by ∼1°. Intense, low-latitude features were also detected. The decrease in emitted power is attributed to a decrease in auroral current density rather than electron energy. This could be caused by a decrease in the source electron density, an order of magnitude increase in the source electron thermal energy, or a combination of these. Both can be explained either by expansion of the magnetosphere or by an increase in the inward transport of hot plasma through the middle magnetosphere and its interchange with cold flux tubes moving outward. In the latter case the hot plasma could have increased the electron temperature in the source region and produced the intense, low-latitude features, while the increased cold plasma transport rate produced the shift of the main oval.