*Seiya Nishizawa1, Masatsugu Odaka2, Yoshiyuki O. Takahashi3, Ko-ichiro SUGIYAMA4, Kensuke Nakajima5, Masaki Ishiwatari2, Shin-ichi Takehiro6, Hisashi Yashiro1, Yousuke Sato1, Hirofumi Tomita1, Yoshi-Yuki Hayashi3
(1.RIKEN AICS, 2.Hokkaido Univ., 3.Kobe Univ., 4.ISAS, 5.Kyushu Univ., 6.Kyoto Univ.)
Keywords:Mars, dust devil
Martian dust devil has an important role in Martian atmospheric circulation, and we examine statistics of Martian dust devil with a high-resolution (up to 5 m) and wide-domain (about 20 x 20 km2) large-eddy simulation of the Martian planetary boundary layer. In this study, we define strong isolated vortex as dust devil. We clarified the distributions of size and intensity and concluded that the maximum vertical vorticity of an individual dust devil has an exponential distribution, while the radius and circulation have power-law distributions.
We also examine dependency of the statistics on experimental resolution with a grid-refinement experiment. These statistics will lead to more accurate estimation of dust injection from the surface to the atmosphere and a more sophisticated parameterization of the dust injection for use in general circulation models.