Aeronomy of the current Martian atmosphereThe thermal structure of the Martian atmosphere, which varies diurnally, seasonally and episodically, is discussed. The atomic oxygen airglow at 1304 A is used to determine the density of atomic oxygen, and the 1216-A Lyman-alpha line is used to calculate the density of atomic hydrogen and, when coupled with the temperature measurement, the escape flux of atomic hydrogen. The most intense airglow is the IR atmospheric band of O2 at 1.27 micron that results from the photodissociation of ozone. The escape mechanism for atomic hydrogen is thermal, or Jeans, escape, while the atomic oxygen escape is caused by a nonthermal process, namely, the dissociative recombination of O2(+). The ratio of deuterium to hydrogen is enriched by a factor of 6. Three-dimensional models of the Mars thermospheric circulation show that planetary rotation has a significant effect on the wind, composition, and temperature structure.
Document ID
19930043885
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Barth, C. A. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Stewart, A. I. F. (Colorado Univ. Boulder, United States)
Bougher, S. W. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Hunten, D. M. (Arizona Univ. Tucson, United States)
Bauer, S. J. (Graz Univ. Austria)
Nagy, A. F. (Michigan Univ. Ann Arbor, United States)