Liquid Containing Clouds at the North Slope of Alaska Demonstrate Sensitivity to Local Industrial Aerosol Emissions

Abstract

Cloud condensation nucleus control alter cloud solar albedo through cloud droplet size. Here, we leverage anthropogenic emissions at the North Slope of Alaska as a natural laboratory to study relationships between aerosols and Arctic liquid-containing clouds. Averaging 14 years of MODIS observations, we found a reduction in temporally averaged cloud effective radius ((Formula presented.)) of up to 1.0 μm related to localized pollution. Pronounced regional gradients in cloud frequency of occurrence and liquid water path prohibit the detection of potential changes of these variables. Observed changes of (Formula presented.) alter radiative fluxes and increase cloud-reflected shortwave radiation by up to 0.8 W m−2 in the Prudhoe Bay area for the period covered by observations (April–September). Due to the frequent occurrence of liquid-containing clouds, this implies that enhanced local emissions in Arctic regions can impact climate processes.