Modeling the Thermosphere as a Driven-Dissipative Thermodynamic System

Author

William R. Frey

Date of Award

3-21-2013

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Engineering Physics

First Advisor

Matthew B. Garvin, PhD.

Abstract

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, T_1/2 , defined by Jacchia, 1977 (J77), is modeled using the magnetospheric electric field as a driver. Three methods of treating the UV contribution to T_1/2 (T_1/2UV) are tested. Two model parameters, the coupling and relaxation constants, are adjusted for 38 storms from 2002 - 2008 to minimize modeled T_1/2 errors. Observed T_1/2 values are derived from densities and heights measured by the GRACE satellite. It is found that allowing T_{1/2 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 T_1/2UV as a constant produces the lowest errors for 7 of 10 storms with increasing UV contributions.

AFIT Designator

AFIT-ENP-13-M-11

DTIC Accession Number

ADA582255

Recommended Citation

Frey, William R., "Modeling the Thermosphere as a Driven-Dissipative Thermodynamic System" (2013). Theses and Dissertations. 926.
https://scholar.afit.edu/etd/926