HR: 17:30h
AN: P34A-07 INVITED     [Abstracts]
TI: Three-Dimensional Climate Modeling of the Amazonian Environment and Glaciation
AU: * Richardson, M I
EM: mir@gps.caltech.edu
AF: California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 United States
AU: Mischna, M A
EM: michael.a.mischna@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Dr, Pasadena, CA 91109 United States
AB: Spacecraft data increasingly suggest that Mars has experienced dramatic changes in the distribution of surface and subsurface water ice in the recent past, potentially associated with rather different climate states. In the limit of high obliquity, this likely corresponds to tropical water ice sheets, while in the low obliquity limit, it corresponds to atmospheric collapse. Climate models suggest that such changes in the planetary environment and water distribution are expected on the basis of the large change in planetary orbital parameters on time scales >10{⁵} yrs. These variations are quazi-cyclical, and so are expected to have caused ongoing (non-secular) changes in climate throughout the Amazonian. Indeed, some orbital forcing of climate may be involved in the episodes of raised and lowered water table in Terra Meridiani, as inferred from Opportunity observations. It is believed that superposed on this quazi-cyclical pattern is a signal of net atmospheric deflation, due primarily to loss to space. The challenge for climate dynamics is to explain the nature and extent of climate change through time, with a particular focus on the changing distribution and stability of water. This presentation will review developments to date, model sensitivities, and future directions.
DE: 4946 Milankovitch theory
DE: 5405 Atmospheres (0343, 1060)
DE: 5416 Glaciation
DE: 5462 Polar regions
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: Fall Meeting 2005