The dynamic model is UW-NMS (Tripoli and Smith 2014ab) and the cloud microphysical scheme is AMPS (Hashino and Tripoli 2007, 2008, 2011ab). The ice part of AMPS (SHIPS) is designed to predict ice crystal habits explicitly, thus it is suitable to study ice nucleation process for the mixed-phased clouds. The case studies were chosen from SHEBA (Surface Heat Budget of the Arctic Ocean) and ISDAC (Indirect and Semi-Direct Aerosol Campaign) field campaigns.
So far, we have found, in a parcel model setting, that a Bigg-type time-dependent immersion freezing parameterization (Kao-Bigg) differs from the classical nucleation theory approach (CNT) significantly in terms of the temperature of nucleation and resulting number concentration. Differences also appear on the spatial distribution of habits in 2D LES simulation. For the SHEBA case, the immersion freezing with CNT triggers freezing of droplets right after they are activated, so the active region is collocated with small droplets and temperature of irregular polycrystals. On the other hand, Kao-Bigg is associated with large cloud droplets and temperature of planar growth. We will discuss more on the simulated habits with 3D LES in the presentation.