Unified Retrieval of Cloud Properties, Atmospheric Profiles, and Surface Parameters from Combined DMSP Imager and Sounder Data

摘要

The main objective of the proposed study was to investigate the complementary information provided by microwave and infrared sensors in order to enhance both the microwave retrieval and the current cloud analysis. This primary task investigated and assessed the impact of incorporating cloud horizontal and vertical spatial distribution information on the performance and accuracy of simultaneous physical retrievals of atmospheric profiles from microwave sensors. The second task explored additional attributes of the microwave measurements, particularly related to ice clouds, to investigate the possibility of identifying multi-layer clouds from simultaneous microwave, visible and infrared data, and to provide infrared emission properties needed for threshold-based cloud detection. We also applied the UR approach to DMSP data to provide the basis for screening out cases where the infrared/visible- derived low cloud properties were uncertain and to assess ability to characterize the vertical structure of multi-layer clouds. The third task investigated the feasibility of predicting infrared emission properties using the microwave data, and assessed if this information could be used to enhance low cloud and thin high cloud identification in totally overcast conditions, especially at night. This task included deriving empirical relationships between microwave and infrared surface emission based on dependent clear data sets, and performing exploratory cloud analyses using both the surface temperature data from the current surface temperature data base and the microwave derived surface emission properties. The last task addressed the application of the UR algorithm to land and to snow/ice backgrounds and assessed the algorithm's capability using new data collected over the Northern Hemisphere in the winter.