AOSC Seminar
November 10, 2016

Insights into subtropical cloud feedback mechanisms from high-resolution simulations

Chris Bretherton
Atmospheric Sciences and Applied Mathematics, University of Washington, WA

This talk addresses the application of cloud-resolving and large-eddy simulations to low cloud feedbacks on climate change. Large-eddy simulations of subtropical cloud-topped boundary layers produce less stratocumulus cloud (positive feedback) in response to warming and increased CO2, modulated by stratification changes. We find that similar mechanisms govern patterns of low cloud sensitivity to a prescribed SST increase in near-global aquaplanet simulations with cloud-resolving (4 km) horizontal resolution, as well as in a superparameterized climate model. A better mechanistic understanding of cloud feedback is aiding interpretation of the historical record and decadal variability as constraints on climate sensitivity.