The Atmospheric Response to a Stratospheric Dust Cloud as Simulated by a General Circulation Model

Results of using the RAND version of the Mintz-Arakawa general circulation model to investigate the initial atmospheric response to a stratospheric dust cloud spread uniformly in a zone between 25° N and 75° N. The dust particles, construed to be two microns or less in diameter, have a total volume comparable to the ejecta of Krakatoa in 1883. The model was integrated for a simulated period corresponding to January and February, the results being compared with those of a control run starting with the same initial conditions and simulating the same period. The temperature below the dust cloud cooled 2 to 3° and the land/ocean temperature contrasts increased. Precipitation varied as a result of changes in the circulation and moisture flux. Midlatitude Ferrel circulations were weakened; baroclinicity decreased at high latitudes and increased at low.