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[27.03] Ground-Based Observations Of Ozone On Mars And Probing Martian Photochemistry

K. E. Fast, T. Kostiuk, J. Annen, F. Espenak (NASA/GSFC), G. Sonnabend (NAS/NRC/GSFC), T. A. Livengood (USRA), T. Hewagama, M. F. A'Hearn (UMD)

Ozone (O₃) is an important tracer of the odd-hydrogen (HO_X) chemistry thought to be responsible for the stability of Mars’ CO₂ atmosphere. Infrared heterodyne spectroscopy with a resolving power of 1-5 x 10⁶ is the only technique that can directly measure fully-resolved line shapes of Martian atmospheric ozone features from the ground. We present ozone column abundances retrieved from 9.7 micron observations made between 1988 and 2003 at various latitudes and orbital positions (L_S = 40, 74, 102, 115, 202, 208, 291). The observed behavior of ozone with latitude and season generally support three-dimensional photochemical model predictions, with low-latitude aphelion disagreement pointing to possible odd-hydrogen loss onto cloud particles. Retrieved total ozone column abundances show varying degrees of anticorrelation with contemporaneous water vapor measurements, pointing to the role of constituent vertical distribution. Generally good agreement is found between infrared heterodyne and ultraviolet ozone retrievals at similar L_S.

This work was supported by the NASA Planetary Astronomy Program.

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Bulletin of the American Astronomical Society, 37 #3
© 2004. The American Astronomical Soceity.