Quantifying the Indirect Effect in Warm Marine Stratocumulus

The sign and magnitude of the indirect effect is still uncertain in climate models due to a poor understanding of the governing factors to the cloud response. The aerosol indirect effect has been quantified using four years of collocated NASA A-Train satellite measurements in the Southeast Pacific and South Atlantic. Estimated inversion strength and the column water vapor are used to account for differing local meteorology in the regions and constrain the cloud to regimes of cloud response. The indirect effect is estimated for each regime in each region and compared. The dependence of in the indirect effect on regime will be demonstrated. Future work will include disentangling the effects of aerosol on the probability of precipitation and the relationship between precipitation and changes to outgoing radiation.