SA31D-2365
Subauroral Ion-neutral Coupling During the March 2015 Superstorm
Wednesday, 16 December 2015
Poster Hall (Moscone South)
Shunrong Zhang1, Philip John Erickson1, John C Foster1, John M Holt1, Anthea J Coster1, Jonathan J Makela2, John Noto3, John W Meriwether4, Yuichi Otsuka5, Michael J Nicolls6 and Mary A McCready6, (1)MIT Haystack Observatory, Westford, MA, United States, (2)University of Illinois, Urbana, IL, United States, (3)Organization Not Listed, Washington, DC, United States, (4)Clemson University, Clemson, SC, United States, (5)Nagoya University, Solar terrestrial Environment Laboratory, Nagoya, Japan, (6)SRI International Menlo Park, Menlo Park, CA, United States
Abstract:
The arrival of solar Coronal Mass Ejection materials overlapping a high-speed solar wind stream originated from a nearby coronal hole caused huge magnetic disturbances during March 17-18, 2015. We have coordinated an international campaign to monitor their geospace effects using ground-based facilities, including incoherent scatter radars and Fabry-Perot Interferometers in the America sectors and other instruments in East Asia sectors, forming an observational network along approximately the 60W/120E meridional circle. The presentation will provide highlights of these observations, with a focus on the ion-neutral coupling processes at subauroral and mid-latitudes. One of the most stiking findings is the northward neutral wind surge, observed in multiple sites, accompanying strong westward winds developed at earlier times. We ascribe this unexpected wind disturbances to Subauroal Polarization Stream (SAPS) asscoated strong plasma flows driving ion-neutral coupling. SAPS and strong ion flow were observed by Millstone Hill ISR and DMSP in situ measurements. We will also report the Millstone Hill ISR observations of a significant enhancement in the storm-time molecular ion composition in the F1-region height. This enhancement appears to be caused by strong vertical ion drift due to penetration electric fields.
