Anthropogenic Aerosols and the Dust Bowl

Abstract:

We use a general circulation model (GISS GCM ModelE) to study the impact of anthropogenic aerosols on the 1930s Dust Bowl. The Dust Bowl was primarily forced by anomalous sea surface temperatures, but may have been partially shaped by the large amounts of black carbon emitted at that time. A simulation using observed 1932-1938 sea surface temperature and sea ice distributions reveal drier and warmer conditions in the central U.S. Adding the influence of 1930s anthropogenic aerosols exacerbates the drying and warm conditions (0.2 °C increase over mid-west continental US, and a decrease of -0.1 mm/day of precipitation). We find that these changes are concurrent with a weakening and shift of the Bermuda High.