The thermosphere is one of the highest layers of the Earth’s atmosphere, localized in altitude regions between 90-1000 km, right below the exosphere. Composed of neutral atoms and molecules, or neutral particles, the thermosphere is extremely sensitive to variations of energy input. During the occurrence of moderate or intense geomagnetic storms, large quantities of plasma energy and momentum are deposited in high latitude regions of the thermosphere. Solar wind plasma, previously energized by the magnetosphere, reaches the thermosphere causing the heating and upwelling of neutral particles. The thermosphere disturbances caused by geomagnetic storms affect the orbit of satellites and other objects that fly in that region. Therefore, the study of such effects are extremely important in the scientific and technological view. In this paper, we present a review of the main characteristics of the thermosphere during quiet times (no storms) and during storm times. Then, we discuss the effects caused by the 20 November 2003 geomagnetic storm on the thermosphere. As an example, we present data of neutral density observed by the accelerometer onboard a LEO (low-Earth orbit) satellite during that geomagnetic storm.
Keywords:
Geomagnetic storms; MIT interactions; thermosphere neutral particle upwelling
