Long-term Trends in Plasmapause Location Based on Defense Meteorological Satellite Program (DMSP) Observations
Thursday, 18 December 2014
The DMSP Retarding Potential Analyzer (RPA) provides density measurements of the upper ionosphere and thus can be utilized to identify the ionospheric projection of the plasmapause under appropriate conditions. We have implemented an automated method to identify the plasmapause based on DMSP observations of the light ion trough (LIT), based on the plasmapause identification (PPID) technique developed by Anderson, Johnston, and Goldstein (2008). Data from the DMSP satellites are unique in this application in that they cover an expansive range of time (up to three solar cycles) at high cadence. We apply our method to data sets for the F13 and F15 satellites that span from 1995-2009 and 2000-2012, respectively. We compare these results to both high altitude plasmapause observations and to geomagnetic index-based empirical plasmapause models, assessing dependence of results on solar cycle phase and geomagnetic activity.