Inner Magnetosphere/Subauroral Flow Bursts in the Partial Ring Region and Their Possible Driving by Tail Flow bursts

Wednesday, 17 December 2014: 2:55 PM
Larry R Lyons1, Toshi Nishimura1, Donald L Hampton2, Vassilis Angelopoulos1, Eric Donovan3, Michael J Nicolls4 and Steven Chen4, (1)University of California Los Angeles, Los Angeles, CA, United States, (2)University of Alaska Fairbanks, Fairbanks, AK, United States, (3)University of Calgary, Calgary, AB, Canada, (4)SRI International Menlo Park, Menlo Park, CA, United States
It is well known that meso-scale flow bursts/channels are an important feature of plasma sheet/auroral oval transport. They lead to most magnetosphere-ionosphere disturbances (i.e., PBIs, streamers, substorms), and significantly affect substorm expansion phase activity. Using radar and all-sky-imager observations, we have identified weak, azimuthally moving auroral features near the equatorward boundary of the auroral oval. We find that they are associated with large azimuthal flow bursts in the SAPS region, and we find evidence that they originate from tail flow bursts that are guided to the SAPS by the large-scale evening side convection. This suggests that, in addition to the well-established effects, some tail flow bursts may flow around the Harang reversal and reach the subauroral region of the inner magnetosphere without breaking or bouncing, leading to SAID-like flow enhancements in the SAPS region. We also have preliminary evidence that some of these flow bursts can extend earthward of the pre-existing SAPS region, leading to ring current earthward injections, proton aurora, and EMIC waves that are important for radiation belt electron loss.