Eugene E. Clothiaux - 613 Seminar Series

Pennsylvania State University

Quantifying the feedbacks of clouds on a warming climate has been  particularly challenging. For example, the IPCC 5th Assessment  Report from Working Group 1 contains the following statements in Section TFE.6 - Climate Sensitivity and Feedbacks (Page 82):  "Cloud feedbacks continue to be the largest uncertainty" and  "Clouds respond to climate forcing mechanisms in multiple ways and individual cloud feedbacks can be positive or negative. Key  issues include the representation of both deep and shallow cumulus  convection, microphysical processes in ice clouds and partial cloudiness that results from small-scale variations of cloud-producing and cloud-dissipating processes." The focus of this talk will be on the radiative implications of "partial cloudiness that results from small-scale variations of cloud-producing and  cloud-dissipating processes" and "microphysical processes in ice clouds." Coherence will be introduced in a consideration of the radiative impacts of partial cloudiness and extended to the remote sensing of ice-particle properties at cloud-radar wavelengths. Results from the ice-particle studies will subsequently be used to provide one perspective on ways to move forward in the evaluation of cloud microphysical models using cloud-radar
observations.