[A-AS08] Processes of the Moist Atmosphere Across Scales

[AAS08-12] Evaluation of grid-scale cloud dynamic in the ICON model at different CCN and vertical velocity and its radiative effect

*Marina Shatunova¹, Natalia Chubarova^2,1, Yulia Shuvalova¹ (1.Hydrometeorological Research Center of Russian Federation, 2.Lomonosov Moscow State University)

Keywords:ICON model , Cloud particle formation , Cloud condensation nuclei, Vertical velocity , Cloud radiative effect

Cloud particle formation in NWP model are highly parameterized through it is difficult to describe explicitly all physical and chemical processes occurring between atmospheric aerosol and water vapor. On the other hand, correct forecast of cloud microphysical structure is crucial for radiative budget prediction. In nonhydrostatic weather and climate model ICON (Zängl et al., 2015) two-moment microphysical scheme (Seifert, Beheng, 2006) is used for simulations on scales of 1-2 km. In the scheme the description of cloud particle formation is based on approach considering aerosol – water vapor interaction (Segal, Khain, 2006). Validation of the ICON model results on the cloud microphysical parameters against CLOUDNET observations showed underestimation of the cloud particle number and mean radius. While water vapor content is predicted well the possible reason could be low number of cloud condensation nuclei (CCN) and low vertical velocity considered in the two-moment microphysical scheme. We investigated the contribution of the two mentioned factors. Simulated mean value of CCN number was estimated by the droplet concentration retrieved from MODIS data. CLOUDNET data were used to evaluate vertical velocity at the cloud lower boundary. Additionally we estimated the cloud radiative effect when the particle concentration changes due to CCN and vertical velocity variations.