Water droplets in some clouds can supercool to temperatures where homogeneous ice nucleation becomes the dominant freezing mechanism. In many cloud resolving and mesoscale models, it is assumed that homogeneous ice nucleation in water droplets only occurs below some threshold temperature typically set at -40°C. However, laboratory measurements show that there is a finite rate of nucleation at w...

Abstract. The Earth Clouds, Aerosols and Radiation Explorer (EarthCARE) satellite mission is a joint endeavour developed by the European Space Agency (ESA) Japan Aerospace Exploration (JAXA) features 94 GHz Doppler Cloud Profiling Radar. This paper presents theoretical basis of cloud precipitation microphysics (C-CLD) EarthCARE Level 2 (L2) algorithm. C-CLD algorithm provides best estimates ver...

This study investigates the effects of aerosols on tropical deep convective clouds (DCCs). A series of largescale, two-dimensional cloud-resolving model simulations was completed, differing only in the concentration of aerosols available to act as cloud condensation nuclei (CCN). Polluted simulations contained more DCCs, wider storms, higher cloud tops, and more convective precipitation domainw...

First, a hybrid cloud microphysical model was developed that incorporates both Lagrangian and Eulerian frameworks to study quantitatively the effect of cloud condensation nuclei (CCN) on the precipitation of warm clouds. A parcel model and a grid model comprise the cloud model. The condensation growth of CCN in each parcel is estimated in a Lagrangian framework. Changes in cloud droplet size di...

A common deficiency of many cloud-physics parameterizations including the NASA’s microphysics of clouds with aerosol-cloud interactions (hereafter called McRAS-AC) is that they simulate lesser (larger) than the observed ice cloud particle number (size). A single column model (SCM) of McRAS-AC physics of the GEOS4 Global Circulation Model (GCM) together with an adiabatic parcel model (APM) for i...

The impact of model microphysics on the retrieval of cloud properties based on passive microwave observations was examined using a three-dimensional, nonhydrostatic, adaptive-grid cloud model to simulate a mesoscale convective system over ocean. Two microphysical schemes, based on similar bulk two-class liquid and three-class ice parameterizations, were used to simulate storms with differing am...

Clouds and their radiative impacts are of primary importance to the Arctic climate and, therefore, global climate. Clouds dominate the radiation balance within the cold, dry Arctic atmosphere, and cloudradiation feedbacks are closely linked with the snow/ice-albedo feedback. Despite the importance of clouds in the Arctic, our current understanding of these clouds remains limited. Global climate...