Abstract

The thermal convection in the Martian lower atmosphere is km-size convection; the maximum vertical and horizontal scales of convective cells are 10 km and 5 km, respectively.

The dust-free case: The values of both horizontal and vertical convective wind velocity often exceed 20 m/sec. The instantaneous maximum value of the surface stress associated with the km-size thermal convection reaches  0.04 Pa, which is equal to the threshold value to raise dust from the surface obtained experimentally.

The dusty case: Dust spreads into the convective layer promptly and is well mixed within a few hours. The depth of the convection layer becomes shallower and the intensity of convetive wind becomes smaller than those of the dust-free case. Horizontal contrast of radiative heating associated with the dust distribution has negligible effect on the morphology of convection. 


Some of the materials in this presentation can be also seen followings. 
dust-free case: Odaka, M., 2001: Geophys. Res. Lette., 28, 895-898.
movie                : Odaka, et al., 2001: http://www.nagare.or.jp/mm/2001/ (now printing)
model                : Nakajima & Odaka, 2000: http://www.gfd-dennou.org/arch/deepconv/