ICE microphysical properties and their relation to dissipation process observed by ship-borne cloud radar

We compared the microphysical properties retrieved by cloud profiling radar with those simulated by GCM, SPRINTARS, along the Mirai cruise tracks in Tropics, Mid-latitude and the Arctic. Prior to the detailed comparison of microphysics, the cloud patterns in GCMs were tested against observations and in general, good agreement was achieved. The comparison was focused on the IWCs (IWC_GM and IWC_IN), r_eff and their inter-relationship. Common features in the model's r_eff and IWCs were the narrow dispersion and large peak value in their frequency distribution. For comparison in the mean vertical profiles of the microphysics, over/under estimation were found in the model's r_eff at high (above 8 km)/low (from 6 km to 8 km) altitudes despite the latitude. Notable difference among latitudes are 1) the over-/under prediction of IWC_IN in model at 6<R<8 km in the Tropics and Mid-latitude/the Arctic, and 2) The differences in the dominant contributor (s) (Cf_ice or/and IWC _IN) in the predicted IWC_GM. These results may indicate the latitudinal dependence in the applicability of the cloud schemes used in GCM. The dissipation rates of ice clouds are estimated by the vertical distribution of V_air, V_t and IWC_IN obtained by the radar. It is shown that the mass fluxes are positive on average in the upper troposphere despite the region, while they become negative and large in magnitude as the altitude decreases. Such sedimentation rate, especially at 6<R<8 km, is the smallest in the Arctic and largest for the Tropics, and may account for the difference seen in the model validation results for IWC_IN among the latitudes. Further validation of the retrieved V_air and microphysics by simultaneous measurements will be provided, and investigation on the relation of the horizontal structure of clouds, cloud microphysics and V_air will be reported during the conference. Then the importance of V_air and V_t at various scales will be addressed in relation to the discrepancies between the observed and simulated microphysics and their effects on the estimation in cloud radiative properties and duration in the model.