Date of Award


Document Type


Degree Name

Master of Science


Department of Engineering Physics

First Advisor

Matthew B. Garvin, PhD.


Thermospheric density impacts satellite position and lifetime through atmospheric drag. More accurate specification of thermospheric temperature, a key input to current models such as the High Accuracy Satellite Drag Model (HASDM), can decrease model density errors. Building on Burke et al. s driven-dissipative model (2009) the arithmetic mean temperature, T1/2 , defined by Jacchia, 1977 (J77), is modeled using the magnetospheric electric field as a driver. Three methods of treating the UV contribution to T1/2 (T1/2UV) are tested. Two model parameters, the coupling and relaxation constants, are adjusted for 38 storms from 2002 - 2008 to minimize modeled T1/2 errors. Observed T1/2 values are derived from densities and heights measured by the GRACE satellite. It is found that allowing T1/2 UV to vary produces the lowest errors for 27 of 38 storms in the sample and 27 of 28 storms with decreasing UV contributions. Treating T1/2UV as a constant produces the lowest errors for 7 of 10 storms with increasing UV contributions.

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