Open AccessCompact Reconnaissance Imaging Spectrometer observations of water vapor and carbon monoxide
Author(s) -
Smith Michael D.,
Wolff Michael J.,
Clancy R. Todd,
Murchie Scott L.
Publication year - 2009
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2008je003288
Subject(s) - mixing ratio , atmosphere of mars , environmental science , water vapor , atmospheric sciences , carbon monoxide , mars exploration program , latitude , northern hemisphere , orbiter , atmosphere (unit) , southern hemisphere , climatology , martian , astrobiology , geology , meteorology , chemistry , physics , astronomy , biochemistry , geodesy , catalysis
The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) onboard the Mars Reconnaissance Orbiter (MRO) spacecraft began taking observations in September 2006 and has now collected more than a full Martian year of data. Retrievals performed using the near‐infrared spectra obtained by CRISM are used to characterize the seasonal and spatial variation of the column abundance of water vapor and the column‐averaged mixing ratio of carbon monoxide. CRISM retrievals show nominal behavior in water vapor during northern hemisphere spring and summer with maximum abundance reaching 50 precipitable micrometers. Water vapor abundance during the southern hemisphere spring and summer appears significantly reduced compared to observations by other instruments taken during previous years. The CRISM retrievals show the seasonally and globally averaged carbon monoxide mixing ratio to be 700 ppm, but with strong seasonal variations at high latitudes. The summertime near‐polar carbon monoxide mixing ratio falls to 200 ppm in the south and 400 ppm in the north as carbon dioxide sublimates from the seasonal polar ice caps and dilutes noncondensable species including carbon monoxide. At low latitudes, the carbon monoxide mixing ratio varies in response to the mean seasonal cycle of surface pressure.