Evaluation of Arctic mixed-phase clouds simulated by a habit-prediction model

In this paper the ability of a habit-prediction cloud microphysical scheme is discussed for simulating Arctic mixed-phase boundary layer clouds. The scheme is the Spectral Ice Habit Prediction System (SHIPS, Hashino and Tripoli 2007, 2008, 2011a, 2011b), the ice module of the Advanced Microphysics Prediction System (AMPS). SHIPS predicts lengths of hexagonal crystals, growth of polycrystals, mass mixing ratios produced by microphysical processes, and circumscribing volumes based on growth history of ice particles. The cases chosen are from the Surface Heat Budget of the Arctic Ocean (SHEBA) and from the Indirect and Semi-Direct Aerosol Campaign (ISDAC). Previously, AMPS has been utilized for simulating the clouds with 2D settings to show that the immersion-freezing hypothesis can be a working mechanism to explain the discrepancy between observed IN and measured one (de Boer et al. 2010, 2013). As a next step to prove the effectiveness of this modeling approach, we will implement 3D LES simulation and evaluate the predicted habits and size distributions mainly against ground-based lidar and cloud radar with reference to available in-situ observation. The lidar and radar backscattering signals will be calculated based on the predicted habit with a satellite data simulator. As shown by previous studies (van Diedenhoven et al. 2009 and Avramov et al. 2011), the lidar depolarization and Doppler velocity are especially effective for this purpose. The differences of predicted habit and signals between the two cases will be discussed in the presentation.