ECE: Electrical & Computer Engineering
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Electromagnetics

Space@VT

The Center for Space Science and Engineering Research investigates space weather and its interactions with the Earth.

Modeling how geomagnetic storms heat the ionosphere, create satellite drag

Geomagnetic storms generate a changing heat pattern in the upper atmosphere, which creates a drag on low-orbit satellites and debris. ECE’s Dan Weimer wants to better predict this drag through improved models and has been awarded a three-year, $375,000 grant from NASA to support the effort.

The interaction of solar wind with the Interplanetary Magnetic Field (IMF) causes significant energy transfer to the ionosphere at high latitudes. “This leads to added heat in the upper atmosphere and thermosphere, the same interaction that is associated with the aurora,” he explains. In major geomagnetic storms, this heating causes low-altitude satellites to experience a higher drag force, which results in problems with their tracking, he says.

Weimer is comparing the heat flowing into the thermosphere from different sources. He is focusing particularly on the change in the global temperature of the thermosphere during geomagnetic storms. He also will be improving the empirical models that calculate the ionospheric electric fields and currents. The thermosphere is the part of the upper atmosphere above 90 km (56 miles) where the temperature rapidly increases from -170°F to more than 1200°F, due to heating by solar ultra-violet radiation.