[P-PS04] Recent advances in the science of Venus

[PPS04-15] Toward a Mesoscale Dynamics and Microphysical Cloud Model for Venus

*Kevin McGouldrick¹、Erika L. Barth² (1.University of Colorado Boulder、2.Southwest Research Institute)

キーワード：Venus, Atmosphere, Clouds, Dynamics

The clouds of Venus play a key role in the radiative balance of the planet. The clouds reflect more than 75% of the incident sunlight, while an atmospheric constituent (which is possibly also an aerosol) that is co-located with the clouds is responsible for absorbing approximately half of what incident sunlight remains. The clouds also play a relatively minor but significant role in the greenhouse warming of the planet, particularly in the mid-infrared where the imaginary refractive index of the sulfuric acid cloud dropets begins to become significant. In addition to all of this, the middle and lower clouds are sustained through a radiative-dynamical feedback in which heating of the cloud base by upwelling infrared radiation from the deep atmosphere, and more importantly, radiative cooling from the top of the middle cloud deck to space sustains a vertical temperature gradient through the clouds that is moderately unstable to convective mixing. Some previous microphysical models explicitly parameterized this radiative-dynamical feedback; but most investigations simply account for the vertical mixing by using a static eddy diffusion coefficient profile. Here, we present initial steps toward the development of a mesoscale dynamics and microphysics model of the Venus clouds that takes full account of this interaction between cloud microphysics, radiative transfer, and local dynamics.