SM31D-4238:
An Extreme Hot Flow Anomaly and Its Geoeffects
Wednesday, 17 December 2014
Hui Zhang, University of Alaska Fairbanks, Fairbanks, AK, United States, Qiugang Zong, Peking University, School of Earth and Space Sciences, Beijing, China, David G Sibeck, NASA/GSFC, Greenbelt, MD, United States and Nojan Omidi, Solana Scientific Inc., Solana Beach, CA, United States
Abstract:
Hot flow anomalies (HFAs) are events observed near planetary bow shocks that are characterized by greatly heated solar wind plasmas and substantial flow deflection. HFAs are universal phenomena that have been observed near the bow shock of Earth, Venus, Mars, and Saturn. A typical HFA lasts from 30s to a few minutes. We report THEMIS observations of an extreme HFA near the prenoon bow shock which lasted 17 minutes from 0717 UT to 0734 UT on 12 August 2007. The magnetopause bulged out by at least 4 RE. Timing analysis shows that the bulge convected tailward with the magnetosheath flow at ~100 km/s. Observations of the IMAGE magnetometer network at 9 MLT show clear response to this extreme HFA. The ionospheric equivalent currents show a strong eastward component at 76-79 degree latitude. The Cluster spacecraft located in the dawnside magnetotail also observed a clear response to this extreme HFA.
