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PhD Defense: Dan Miller

Friday, October 13, 2017
1:00 PM - 4:00 PM
Physics : 401
ADVISOR: Dr. Zhibo Zhang

TITLE: Satellite Simulator Studies of the Impact of Cloud Heterogeneity on Passive Cloud Remote Sensing Retrievals

ABSTRACT:
Satellite cloud remote sensing provides us the opportunity to study the spatial and temporal distributions of marine boundary layer clouds, as well as their connections with environments on a global scale. However, cloud remote sensing is not without difficulties; retrievals require numerous simplifying assumptions, placing limits on our understanding of cloud processes. Passive remote sensing retrievals often assume that clouds are homogeneous slabs, when in reality, these clouds often have complex inhomogeneous vertical and horizontal structures. Enhancing our understanding of how cloud inhomogeneity influences passive cloud remote sensing requires comparison between cloud retrievals and the the underlying cloud properties. In observational data-sets this can become problematic, as it is difficult to compare satellite and airborne measurements because they have both different observed spatial scales and sensitivities to cloud properties. To avoid these complications, this work is based on a satellite retrieval simulator -- a Large-Eddy Simulation (LES) cloud model coupled to radiative transfer and retrieval algorithms. The LES-satellite simulator can be used to study the source of retrieval biases. It provides the underlying realistic cloud structure as a reference, informing conclusions about its impact on various cloud retrieval methods. The simulator is used to test the impact of cloud vertical profile and horizontal inhomogeneity assumptions, compare retrieval techniques directly to one another, and study the impact of 3-D radiative transfer on cloud remote sensing