This paper discusses aircraft observations and large-eddy simulation (LES) modeling of 15 May 2008, North Sea boundary-layer clouds from the EUCAARIIMPACT field campaign. These clouds are advected from the northeast by the prevailing lower-tropospheric winds and featured stratocumulus-over-cumulus cloud formations. An almost-solid stratocumulus deck in the upper part of the relatively deep, wea...

A polar cirrus case study is discussed with the help of a one-dimensional model with explicit aerosol and ice microphysics. It is demonstrated that continuous cooling of air in regions with small amounts of ice and slow ice deposition rates of water vapor drives significant in-cloud supersaturations over ice, with potentially important consequences for heterogeneous halogen activation. Radiativ...

Wetzel and Martin present an ingredients-based methodology for forecasting winter season precipitation. Although they are to be commended for offering a framework for winter-weather forecasting, disagreements arise with some of their specific recommendations. In particular, this paper clarifies the general philosophy of ingredients-based methodologies and shows how the methodology presented by ...

This paper basically follows the title, i.e. it investigates the impact of frost flowers (FF) as an Brsource, recycling of bromine on snow, and the impacts of open leads in the initiation and development of ozone depletion events in the Arctic marine boundary layer. They do this using a sophisticated 1D model with chemistry, microphysics and cloud formation used in a Lagrangian mode and by vary...

[1] A new framework for calculating cloud droplet number, including a continuity equation for cloud droplet number concentration, has been developed and implemented in an extended version of the National Center for Atmospheric Research (NCAR) Community Atmosphere Model version 2.0.1 (CAM-2.0.1). The new continuity equation for cloud droplet number concentration consists of a nucleation term and...

Aerosols alter cloud density and the radiative balance of the atmosphere. This leads to changes in cloud microphysics and atmospheric stability, which can either suppress or foster the development of clouds and precipitation. The net effect is largely unknown, but depends on meteorological conditions and aerosol properties. Here, we examine the long-term impact of aerosols on the vertical devel...