Planetary Climate Dynamics

Abstract:

The Composite Infrared Spectrometer observed Jupiter in the thermal infrared during the swing-by of the Cassini spacecraft. Results include the detection of two new stratospheric species, the methyl radical and diacetylene, gaseous species present in the north and south auroral infrared hot spots; determination of the variations with latitude of acetylene and ethane, the latter a tracer of atmospheric motion; observations of unexpected spatial distributions of carbon dioxide and hydrogen cyanide, both considered to be products of comet Shoemaker-Levy 9 impacts; characterization of the morphology of the auroral infrared hot spot acetylene emission; and a new evaluation of the energetics of the northern auroral infrared hot spot.

Abstract:

The Hellas Basis is an impact-formed deep basin in the Southern Hemisphere of Mars. We undertook a limited planning exercise for a human Trans-Hellas expedition that would traverse the basin from West to East. The authors of this paper divided into three teams. The Science Group was set the task of defining science goals for a Trans-Hellas Crossing. The Logistics Group was set the task of considering what transport and accommodation the team would use during the expedition and the Resource Group was set the task of defining resource use and allocation during the traverse. We present the main conclusions of this short study and show that the Hellas Basin should be considered a high priority science target for future human expeditions. We demonstrate the effectiveness of Martian expedition planning using a small team with diverse expertise.

Abstract:

The Mars climate database (MCD) is a database of statistics based on output from physically consistent numerical model simulations which describe the climate and surface environment of Mars. It is used here to predict the meteorological environment of the Beagle 2 lander site. The database was constructed directly on the basis of output from multiannual integrations of two general circulation models, developed jointly at Laboratoire de Météorologie Dynamique du Centre National de la Recherche Scientifique, France, and the University of Oxford, UK. In an atmosphere with dust opacities similar to that observed by Mars Global Surveyor, the predicted surface temperature at the time of landing (Ls=322°, 13:00 local time), is ∼267 K, and varying between ∼186 and 268 K over the Martian day. The predicted air temperature at 1 m above the surface, the height of the fully extended Beagle 2 robot arm, is ∼258 K at the time of landing. The expected mean wind near the surface on landing is ∼5 ms-1 north-westerly in direction, becoming more southerly over the mission. An increase in mean surface pressure is expected during the mission. Heavy global dust storm predictions are discussed; conditions which may only occur in the extreme as the expected time of landing is around the end of the main dust storm period. Past observations show approximately a one in five chance of a large-scale dust storm in a whole Mars year over the landing region, Isidis Planitia. This statistic results from observations of global, encircling, regional and local dust storms but does not include any small-scale dust "events" such as dust devils. © 2003 Elsevier Ltd. All rights reserved.