Dynamical effects of aerosol perturbations on simulated idealized squall lines

An increase in aerosol loading leads to a weakening of the cold pool and, hence, a more optimal balance between the cold pool- and environmental shear-induced circulations according to RKW theory. Consequently, there is an increase in the convective mass flux of nearly 20% in polluted conditions relative to pristine. This strengthening coincides with more upright convective updrafts and a significant increase (nearly 20%) in cumulative precipitation.

An increase in aerosol loading in a strong wind shear environment (0.0064 s-1) leads to less optimal storms and a suppression of the convective mass flux and precipitation. This occurs because the cold pool circulation is weak relative to the environmental shear when the shear is strong, and further weakening of the cold pool with high aerosol loading leads to an even less optimal storm structure (i.e., convective updrafts begin to tilt downshear).