ASTRA - Atmospheric & Space Technology Research Associates, LLC

Mars-GCM

Temperature and Winds

Figure 1 shows the ASPEN global distribution of Mars’ winds and temperatures at 100 km altitude, as a function of latitude and local time, for Ls = 270 (northern winter solstice) moderate solar activity (F10.7=150) conditions at 00UT. Superposed on Figure 1 is a line showing one of the Mars Odyssey aerobraking passes (orbit 170) near solstice extending over the pole. Crowley et al (2006) showed that the model agrees well with the Odyssey measurements for this time period.

Figure 2 illustrates the global mean temperature structure (purple curve) from the ASPEN model for Equinox solar maximum conditions. The figure also contains predictions from the Bougher et al. (1999) model for equinox conditions at 15LT near the equator. The blue, green and red curves depict the Bougher et al results for solar minimum, moderate, and maximum, respectively. The black solid curve shows the ASPEN temperature profile for equinox solar maximum at 15 LT near the equator, and the dotted black curve shows the Nair et al (1994) empirical profile. The figure shows that the ASPEN model obtains results that are similar to Bougher et al, but the ASPEN model extends to much lower altitudes, and captures the middle and lower atmosphere structure down to 14 km. In the middle and lower atmosphere, the ASPEN model matches the Nair profile quite well, although no effort was made to tune the ASPEN profile.