Thermophysics

Themophysics is the study of heat transfer and storage in physical materials.

Remote Sensing

Thermophysics is a branch of geophysics which uses the naturally occurring surface temperature as a function of the cyclical variation in solar radiation to charactertize planetary material properties.

Thermophysical properties are characteristics that control the diurnal, seasonal, or climatic surface and subsurface temperature variations (or thermal curves) of a material. The most important thermophysical property is thermal inertia, which controls the amplitude of the thermal curve and albedo (or reflectivity), which controls the average temperature.

This field of observations and computer modeling was first applied to Mars due to the ideal atmospheric pressure for characterizing granular materials based upon temperature [Wechsler and Glaser, 1965] . The Mariner 6, Mariner 7, and Mariner 9 spacecraft carried thermal infrared radiometers which mapped the power readings of the core of the planet [Neugebauer, et al., 1971; Kieffer et al., 1973] , and a global map of thermal inertia was produced from modeled surface temperatures [Kieffer, et al., 1977] collected by the Infrared Thermal Mapper Instruments (IRTM) on-board the Viking 1 and 2 Orbiters.

The original thermophysical models were based upon the studies of lunar temperature variations by Wesselink [1948] and Jaeger [1953] . Further development of the models for Mars included surface-atmosphere energy transfer [Leovy, 1966] , atmospheric back-radiation [Neugebauer et al., 1971] , surface emissivity variations [Kieffer et al., 1973] , CO2 frost and blocky surfaces [Kieffer et al., 1977] , variability of atmospheric back-radiation [Haberle and Jakosky, 1991] , effects of a radiative-convective atmosphere [Hayashi et al., 1995] , and single-point temperature observations [Jakosky et al., 2000; Mellon et al., 2000] .

References

Wechsler, A.E., and P.E. Glaser, Pressure Effects on Postulated Lunar Materials. Icarus, Vol. 4, 335, 1965.

Neugebauer, G., G. Munch, H.H. Kieffer, S.C. Chase, and E. Miner, Mariner 1969 Infrared Radiometer Results: Temperatures and Thermal Properties of the Martian Surface. Astronomical Journal, Vol. 76, 719, 1971.

Kieffer, H.H., S.C. Chase, E. Miner, G. Munch, and G Neugebauer, Preliminary Report on Infrared Radiometric Measurements from the Mariner 9 Spacecraft. J. Geophys. Res., 78, 4291-4312, 1973.

Kieffer, H.H., T.Z. Martin, A.R. Peterfreund, B.M. Jakosky, E.D. Miner, and F.D. Palluconi, Thermal and Albedo Mapping of Mars During the Viking Primary Mission. J. Geophys. Res., Vol. 82, No. 28, 4249-4290, 1977.

Wesselink, A.J., Heat conductivity and nature of the lunar surface material. Bull. Astron. Inst. Neth., Vol. 10, 351-363, 1948.

Jaeger, J.C., The Surface Temperature of the Moon., Australian Journal of Physics, vol. 6, p.10, 1953.

Leovy, C., Note on the thermal properties of Mars., Icarus, 5, 1-6, 1966.

Haberle, R.M., and B.M. Jakosky, Atmospheric effects on the remote determination of thermal inertia on Mars. Icarus, 90, 187-204, 1991.

Hayashi, J.N., B.M. Jakosky, and R.M. Haberle, Atmospheric effects on the mapping of Martian thermal inertia and thermally derived albedo. J. Geophys. Res. Vol. 100, E3, 5277-5284, 1995.

Jakosky, B.M., M.T. Mellon, H.H. Kieffer, P.R. Christensen, E.S. Varnes, and S.W. Lee, The Thermal Inertia of Mars from the Mars Global Surveyor Thermal Emission Spectrometer. J. Geophys. Res., 105, 9643-9652, 2000.

Mellon, M.T, B.M. Jakosky, H.H. Kieffer, and P.R. Christensen, High Resolution Thermal Inertia Mapping from the Mars Global Surveyor Thermal Emission Spectrometer. Icarus, 148, 437-455, 2000.