Extreme poynting flux in the dayside thermosphere: Examples and statistics

With the launch of the Defense Meteorological Satellite Program F-15 spacecraft in late 1999, data for calculating Earth-directed, magnetospheric Poynting flux became available for the 09-21 solar local time sectors. We have assembled a data base for this key element of the upper atmosphere energy budget, for the interval 2000-2005. Here we briefly introduce the data set and show a subset that reveals a pattern of extreme Poynting flux deposition associated with a large east-west interplanetary magnetic field component. At such times the dayside high-latitude Poynting flux may exceed 170 mW/m2--an order of magnitude above typical values. The likely source of these events is merging at the magnetopause flank and lobe. A significant fraction of these events occur with high speed solar wind. This pattern of extreme Poynting flux deposition has, to date, eluded detection. Energy deposition at these high rates is a likely source of previously reported, but poorly understood, near-cusp neutral density enhancements.