The goal of our work is to develop and evaluate a prognostic The aqueous reaction to convert SO to in clouds is aerosol model and to parameterize the effects of aerosols, actassumed to have an average e-folding lifetime of 30 hours at ing as cloud condensation nuclei (CCN), on initial cloud drop40° N at the surface in summer. This e-folding lifetime is let concentrations. This, together with gl...

We have investigated the sensitivity of the intensity of convective activity and atmospheric radiative cooling to radiatively thick upper-tropospheric clouds using a new version of the Colorado State University General Circulation Model. The model includes a bulk cloud microphysics scheme to predict the formation of cloud water, cloud ice, rain, and snow. The cloud optical properties are intera...

[1] A two-moment bulk microphysical scheme has been implemented into the Weather Research and Forecasting (WRF) model to investigate the aerosol-cloud interaction. The microphysical scheme calculates the mass mixing ratios and number concentrations of aerosols and five types of hydrometeors and accounts for various cloud processes including warm and mixed phase microphysics. The representation ...

The formulation of the cloud-radiation feedback is compounded by extreme variability of clouds over a wide range of scales. In this study, we address the problem of geometry and spatial inhomogeneity in stratiform cloud layers and its influence on cloud optical depth. The investigation is based on the Cooperative Institute for Mesoscale Meteorological Studies (CIMMS) large eddy simulation model...

Clouds play an immense role in transport and transformation of atmospheric trace species. In the joint project FEBUKO (Field investigations of budgets and conversions of particle phase organics in tropospheric cloud processes) the microphysics and chemistry of different types of aerosols, the role of aerosol chemical composition for cloud formation as well as the chemical transformation in clou...

An existing numerical model of cumulus growth, treating condensation but not precipitation, is modified by the incorporation of a parameterized treatment of liquid phase microphysics. This modification improves the realism of the results in several important respects; among them are maximum height of cloud growth, maximum liquid content, amount and distribution of temperature departure, cloud s...

Two basic methods have been used to relate the change in droplet number concentration to aerosol number concentration. The first method uses empirically derived relationships based on either observed aerosol number concentrations and droplet concentrations or observed aerosol sulfate or droplet mass concentrations and droplet number concentrations. This method was followed by Jones et al. (1994...

Satellite orographic precipitation estimates exhibit large errors with space-time structure tied to landform. Observations in the Southern Appalachian Mountains (SAM) suggest that low-level clouds and fog (LLCF) amplify mid-day rainfall via seeder-feeder interactions (SFI) at both high and low elevations. Here, a rainfall microphysics model constrained by fog observations was used first to reve...