Effects of Arctic Haze on Clouds and the Surface Radiation Balance

Increases in anthropogenic aerosols in the atmosphere tend to increase the reflectance of solar (shortwave) radiation from water clouds, which can lead to lower surface temperatures. Aerosols can also increase the longwave emissivity of thin clouds, thereby warming the surface. The latter effect may be particularly important in the Arctic, especially during the winter and early spring when thin stratus clouds are ubiquitous, relatively high levels of anthropogenic pollution are common, and there is little solar radiation.

This hypothesis is examined using airborne cloud microphysics measurements, surface measurements of aerosol concentrations from the CMDL North Slope of Alaska (NSA) site, and ARM NSA cloud microphysical retrievals.