Poynting Flux Measured on DMSP Satellites and Its Influence on the Thermosphere

Abstract:

High-latitude Joule heating is one of the most significant energy deposition processes from the magnetosphere into the ionosphere-thermosphere system. It can change the temperature structure, atmosphere composition, and electron density and hence influences satellite drag. Using the DMSP observations of ion drift velocities (which can be used to calculate the electric fields) and magnetic fields, the field-aligned Poynting fluxes are calculated. It is found that auroral region is dominated by the download Poynting flux no matter the geomagnetic activity is disturbed or quiet. Clear asymmetries are shown in the two hemispheres in both geographic and geomagnetic coordinates. The energy transported into thermosphere in minimum year of the 22th solar cycle is more than that in the maximum year. The correlations between the Poynting flux and the temperature and density of the thermosphere will also be systematically investigated.