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
