Impacts of Long-Range Biomass Burning and Anthropogenic Pollution Transport on Arctic Clouds

A combination of in situ measurements, tracer transport model simulations, and ground and spaced based remote sensing is showing that pollution plumes alter cloud properties so as to produce an added warming of the surface in winter and spring and an added cooling in summer and fall. These measurements represent a large spatial and time scale perspective, averaged over many years, and for the Arctic as a whole. There have been past anecdotal reports since the 1800s of specific cases where pollution plumes from Europe and elsewhere have created a distinct "Arctic haze" associated with unusually high aerosol loadings at high latitudes. This study extends these storylines by showing specific cases where pollution plumes from Europe, and forest fires from Siberia and Northern Canada, have been blown northward to the Arctic, and have altered cloud microphysical and radiative properties. The study combines MODIS, MISR and POLDER satellite imagery and FLEXPART tracer transport model simulations.