Modeling the Thermosphere as a Driven-Dissipative Thermodynamic System
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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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, T12 , defined by Jacchia, 1977 J77, is modeled using the magnetospheric electric field as a driver. Three methods of treating the UV contribution to T12 T12UV are tested. Two model parameters, the coupling and relaxation constants, are adjusted for 38 storms from 2002 - 2008 to minimize modeled T12 errors. Observed T12 values are derived from densities and heights measured by the GRACE satellite. It is found that allowing T12 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 T12UV as a constant produces the lowest errors for 7 of 10 storms with increasing UV contributions.
- Atmospheric Physics