HR: 09:30h
AN: P21C-07 INVITED    [Abstracts]
TI: The Interannual Record of Water Vapor and Water Ice Clouds at Mars From Spacecraft Observations
AU: * Smith, M D
EM: Michael.D.Smith@nasa.gov
AF: NASA Goddard Space Flight Center, Code 693, Greenbelt, MD 20771, United States
AB: The combination of observations from a number of spacecraft at Mars including Viking, Mars Global Surveyor, Mars Odyssey, Mars Reconnaissance Orbiter, and Mars Express, allows for the comparison of atmospheric conditions across several martian years. The atmospheric component of the martian water cycle, as expressed in terms of water vapor abundance and water ice cloud optical depth, displays a generally repeatable pattern from year to year, with modest interannual variation. The main features of the atmospheric water cycle are present each year. Water vapor has an annual maximum at high northern latitudes during northern summer and a secondary maximum at high southern latitudes during southern summer. Water ice clouds are most abundant in winter polar hoods (especially in the north) and during the aphelion season in the form of a low-latitude cloud belt. However, details in the timing and amplitude of these main features can vary from year to year in response to other phenomena such as large dust storms. For example, an early-season large dust storm at low latitudes late in 2004 (Mars Year 27, L_s=135°), caused an early end to the aphelion season ice cloud belt. Here we discuss the major repeatable features of the atmospheric water cycle and the degree to which interannual variations have been observed by spacecraft observations.
DE: 0343 Planetary atmospheres (5210, 5405, 5704)
DE: 5405 Atmospheres (0343, 1060)
DE: 5464 Remote sensing
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting