HR: 1340h
AN: P13A-0139    [Abstracts]
TI: Outflow Channels and Martian Climate: General Circulation Model (GCM) Simulations with Emplaced Water and Cloud Physics
AU: * Santiago, D
EM: dsantiago@es.ucsc.edu
AF: UC Santa Cruz, Department of Earth Sciences 1156 High Street, Santa Cruz, CA 95064 United States
AU: Colaprete, A
EM: tonyc@freeze.arc.nasa.gov
AF: NASA Ames Research Center, NASA Ames Research Center, Moffett Field, CA 94035 United States
AU: Haberle, R
EM: Robert.M.Haberle@nasa.gov
AF: NASA Ames Research Center, NASA Ames Research Center, Moffett Field, CA 94035 United States
AU: Asphaug, E
EM: asphaug@es.ucsc.edu
AF: UC Santa Cruz, Department of Earth Sciences 1156 High Street, Santa Cruz, CA 95064 United States
AU: Sloan, L
EM: lcsloan@es.ucsc.edu
AF: UC Santa Cruz, Department of Earth Sciences 1156 High Street, Santa Cruz, CA 95064 United States
AB: One of the most intriguing signatures of surface water on Mars is large outflow channels believed to have been carved out by gigantic flood events in the late Noachian or Hesperian. We use the NASA Ames Mars General Circulation Model (MGCM) to study how abrupt eruption of water onto the Martian surface might have affected the early climate of Mars, and to calculate where the water ultimately went as part of a transient hydrologic cycle. Our model includes the emplacement of large amounts of water onto the surface of a cold, dry Mars in the vicinity of Ares Valles, with current day orbital configurations. Specifically, 10⁶ km³ of water was released at a rate of 0.1 km³/s at end of Northern Hemisphere summer. We have begun modeling with the MGCM with outflow water and cloud physics. The current cloud physics include cloud particle nucleation and growth, with radiative effects added at a later date. These results are being compared with a control case with no outflow in the model, and a case with water, but without clouds. In all cases we are examining the radiative effects of water vapor, albedo effects of water ice, and latent heat effects for this large influx of water. Preliminary results show differences between these three cases, but the factors that are causing these differences have not yet been determined. These results will be interesting to compare with studies that suggest significant, but possibly localized or regional, precipitation in the Hesperian, as opposed to the more widely recognized precipitation during the Noachian. Current analyses and longer model runs will allow us to calculate the specific effects of outflow water on past Martian climate, as well as where the water might have ended up.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 3300 ATMOSPHERIC PROCESSES
SC: Planetary Sciences [P]
MN: Fall Meeting 2005