Arctic clouds modulate the surface radiation budget by emitting longwave radiation and reflecting incident shortwave radiation. The Arctic is characterized by high levels of anthropogenic pollution that commonly forms a haze in winter and spring, due to long-range transport of aerosols primarily from Eastern Europe and Russia (Sirois and Barrie, 1999). During the Arctic winter and spring strong...

Loadings of tropospheric aerosols have increased substantially over the past 150 yr as a consequence of industrial activities. These aerosols enhance reflection of solar radiation by the Earth-atmosphere system both directly, by scattering light in clear air and, indirectly, by increasing the reflectivity of clouds. The magnitude of the resultant decrease in absorption of solar radiation is est...

Clouds and their associated shadows are major obstacles to most land surface remote sensing applications. Meanwhile, solar-cloud-satellite geometry (SCSG) makes the effect of clouds and shadows on derived land surface biophysical parameters more complicated. However, in most existing studies, the SCSG effect has been frequently neglected although it is pointed out by many works that SCSG effect...

1. introduction the process by which the net radiation is transformed to the atmospheric dynamical energy, occur to a large degree at the interface between the surface and the atmosphere. as the driving force for such process, an accurate estimation of the net radiation at the earth’s surface is a necessary input for surface process models. net radiation is a key component in the surface radiat...

This paper describes a new method for parameterizing the conversion of convective cloud liquid water to rainfall (‘‘autoconversion’’) that can be used within large-scale climatemodels, and evaluates the newmethod using the Regional Climate Model, version 3 (RegCM3), coupled to the land surface scheme Integrated Biosphere Simulator (IBIS). The new method is derived from observed distributions of...

Algorithms linked to form focused chains of algorithms are needed to fill gaps between often measured or available data resources and the parameters requested by many solar applications. This paper describes the formulation of a chain of algorithms for shortwave radiation. The basic inputs into the chain are monthly mean values of the Linke turbidity factor and global radiation. The outputs of ...

The new double-moment microphysics scheme described in Part I of this paper is implemented into a single-column model to simulate clouds and radiation observed during the period 1 April–15 May 1998 of the Surface Heat Budget of the Arctic (SHEBA) and First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment–Arctic Clouds Experiment (FIRE–ACE) field projects. Mean predi...

A new one-dimensional radiative equilibrium model is built to analytically evaluate the vertical profile of the Earth's atmospheric radiation entropy flux under the assumption that atmospheric longwave radiation emission behaves as a greybody and shortwave radiation as a diluted blackbody. Results show that both the atmospheric shortwave and net longwave radiation entropy fluxes increase with a...

Modeled differences in predicted effects are increasingly used to help quantify the uncertainty of these effects. Here, we examine modeled differences in the aerosol indirect effect in a series of experiments that help to quantify how and why model-predicted aerosol indirect forcing varies between models. The experiments start with an experiment in which aerosol concentrations, the parameteriza...