Global distribution of electron temperature enhancement at mid-low latitudes observed by DMSP F16 satellite

Electron temperature enhancements occurred mainly over the North American-Atlantic (260 degrees-360 degrees E) and Eurasia (0 degrees-160 degrees E) (Southern Oceania (80 degrees-280 degrees E)) sector in the Northern (Southern) Hemisphere and are prominent in the winter hemispheres and solar maximum year.

They have obvious longitude characteristics. Interestingly, they could extend to geomagnetic equatorial regions in the North American-Atlantic sector from high to low latitudes in the December Solstice, further crossed the magnetic equator, and merged into the Southern Hemisphere in 2014, where the maximum temperature reached similar to 3500 K. Our analysis indicates that low-energy electrons (<100 eV) associated with photoelectron from the conjugate sunlit hemisphere, can contribute to these enhancements.