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J.R. Murphy (New Mexico State University), T.Z. Martin (Jet Propuslion Laboratory), M. Blackmon, S. Nelli (New Mexico State University)
Stationary and high frequency travelling atmospheric thermal waves on Mars have been quantitatively studied via analyses of temperatures obtained with the Mars Global Surveyor orbiter Horizon Sensor Array (MHSA) instrument. This infrared instrument obtains both in-track and cross-track determinations of martian atmospheric temperature with a vertically broad weighting function. The six local times of coverage provided by these four simultaneous fields of view from MGS's sun-synchronous mapping orbit allow for quantification of eastward and westward travelling diurnal and semi-diurnal atmospheric thermal waves. These high frequency wave (tide) phenomena exhibit seasonal variations due to both changing solar heating and to varying atmospheric dust content.
Comparisons with numerical model results illustrate the viability of the MHSA time/space sampling to provide valid determination of the amplitudes and phases of these wave phenomena. The results from these studies are complimentary to the more vertically resolved but less time-of-sol abundant MGS TES temperatures.
Results of the MHSA analyses indicate the annual persistence of eastward travelling (asynchronous or 'non-travelling') atmospheric tidal modes, and the sensitivity of tidal amplitudes to both season and dust load. Stationary waves at middle latitudes of both hemispheres exhibit significant seasonal variability, as has previously been inferred from TES data and which is theoretically consistent with thermal wind considerations. The accumulating data being obtained by MGS' instruments, including the MHSA, offer the opportunity to investigate interannual atmospheric variability from a self-consistent set of orbital measurements. Current results will be presented. This work has been funded by NASA's Mars Data Analysis Program.
The author(s) of this abstract have provided an email address for comments about the abstract: murphy@nmsu.edu