Variability of Jupiter’s Main Auroral Emission in Response to Magnetospheric Hot Plasma Injections

Tuesday, 16 December 2014
Sarah Victoria Badman1, Bertrand Bonfond2, Masaki Fujimoto3, Masato Kagitani4, Yasumasa Kasaba4, Satoshi Kasahara5, Tomoki Kimura6, Henrik Melin7, Go Murakami8, Jonathan D Nichols9, Takeshi Sakanoi4, Andrew J Steffl10, Chihiro Tao11, Fuminori Tsuchiya4, Takeru Uno4, Atsushi Yamazaki12, Mizuki Yoneda4, Ichiro Yoshikawa13 and Kazuo Yoshioka3, (1)University of Lancaster, Lancaster, LA1, United Kingdom, (2)University of Liège, Laboratoire de Physique Atmosphérique et Planétaire, Liège, Belgium, (3)JAXA Japan Aerospace Exploration Agency, Sagamihara, Japan, (4)Tohoku University, Sendai, Japan, (5)ISAS Institute of Space and Astronautical Science, Kanagawa, Japan, (6)Japan Aerospace Exploration Agency, Kanagawa, Japan, (7)University of Leicester, Leicester, LE1, United Kingdom, (8)ISAS/JAXA, Kanagawa, Japan, (9)University of Leicester, Leicester, United Kingdom, (10)Southwest Research Institute, Boulder, CO, United States, (11)IRAP, Toulouse, France, (12)ISAS/JAXA, Sagamihara, Kanagawa, Japan, (13)University of Tokyo, Bunkyo-ku, Japan
We present observations of Jupiter’s FUV aurora acquired by the Hubble Space Telescope during a two-week interval in January 2014. The variability of the main auroral emission was studied using latitudinal profiles of intensity. The main oval intensity was found to be reduced when bright patches of diffuse emission were present at lower latitudes. These low latitude emissions are interpreted as the signatures of hot plasma injections from the outer magnetosphere, a process which has previously been related to interchange between the flux tubes from the outer magnetosphere and outward-moving flux tubes loaded with iogenic plasma. The main emission was also observed to broaden and shift in latitude, and occasionally display a double peak structure. These observations are interpreted with reference to the expected changes in auroral field-aligned currents associated with the replacement of the radially-stretched, mass-loaded flux tubes in the middle magnetosphere by more dipolar flux tubes containing rarefied hot plasma.