TY - JOUR
T1 - High-resolution atmospheric observations by the Mars Odyssey Thermal Emission Imaging System
AU - Inada, Ai
AU - Richardson, Mark I.
AU - McConnochie, Timothy H.
AU - Strausberg, Melissa J.
AU - Wang, Huiqun
AU - Bell, James F.
N1 - Funding Information:
We acquired the THEMIS visible data from the THEMIS Public Data Releases, Mars Space Flight Facility, Arizona State University ( http://themis-data.asu.edu ). THEMIS data are map projected with Integrated Software for Imagers and Spectrometers (ISIS) provided by USGS. TES data are downloaded from the Mars Global Surveyor Archive at the PDS Geoscience Node and analyzed with a software Vanilla provided by Mars Space Flight Facility, Arizona State University. This work was partially supported by a NASA Mars Data Analysis Program grant to Caltech. We thank to Dr. Philip James and an anonymous reviewer for their useful comments.
PY - 2007/12/15
Y1 - 2007/12/15
N2 - High-resolution observations of atmospheric phenomena by the Mars Odyssey Thermal Emission Imaging System (THEMIS) during its first mapping year are presented. An atmospheric campaign was implemented on the basis of previous spacecraft imaging. This campaign, however, proved of limited success. This appears to be due to the late local time of the Odyssey orbit (the locations of activity at 4-6 p.m. appear to be different from those at 2 p.m.). Ironically, images targeting the surface were more useful for study of the atmosphere than those images specifically targeting atmospheric features. While many previously recognized features were found, novel THEMIS observations included persistent clouds in the southern polar layered deposits, dust or condensate plumes on the northern polar layered deposits, dust plumes as constituent parts of local dust storms, and mesospheric clouds. The former two features tend to be aligned parallel and normal to polar troughs, respectively, suggesting a wind system directed normal to troughs and radially outward from the center of the polar deposits. This is consistent with katabatic drainage of air off the polar deposits, analogous to flow off Antarctica. The observation of dust lifting plumes at unprecedented resolution associated with local dust storms not only demonstrates the importance of mean wind stresses (as opposed to dust devils) in initiation of dust storms, but is also seen to be morphologically identical to dust lifting in terrestrial dust storms. As Odyssey moves to earlier local times, we suggest that the atmospheric campaign from the first mapping year be repeated.
AB - High-resolution observations of atmospheric phenomena by the Mars Odyssey Thermal Emission Imaging System (THEMIS) during its first mapping year are presented. An atmospheric campaign was implemented on the basis of previous spacecraft imaging. This campaign, however, proved of limited success. This appears to be due to the late local time of the Odyssey orbit (the locations of activity at 4-6 p.m. appear to be different from those at 2 p.m.). Ironically, images targeting the surface were more useful for study of the atmosphere than those images specifically targeting atmospheric features. While many previously recognized features were found, novel THEMIS observations included persistent clouds in the southern polar layered deposits, dust or condensate plumes on the northern polar layered deposits, dust plumes as constituent parts of local dust storms, and mesospheric clouds. The former two features tend to be aligned parallel and normal to polar troughs, respectively, suggesting a wind system directed normal to troughs and radially outward from the center of the polar deposits. This is consistent with katabatic drainage of air off the polar deposits, analogous to flow off Antarctica. The observation of dust lifting plumes at unprecedented resolution associated with local dust storms not only demonstrates the importance of mean wind stresses (as opposed to dust devils) in initiation of dust storms, but is also seen to be morphologically identical to dust lifting in terrestrial dust storms. As Odyssey moves to earlier local times, we suggest that the atmospheric campaign from the first mapping year be repeated.
KW - Mars
KW - atmosphere
KW - polar caps
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U2 - 10.1016/j.icarus.2007.07.020
DO - 10.1016/j.icarus.2007.07.020
M3 - Article
AN - SCOPUS:36549079969
SN - 0019-1035
VL - 192
SP - 378
EP - 395
JO - Icarus
JF - Icarus
IS - 2
ER -