DocumentCode :
1053514
Title :
Cloud Optical Depth Retrievals From Solar Background “Signals” of Micropulse Lidars
Author :
Chiu, J. Christine ; Marshak, Alexander ; Wiscombe, Warren J. ; Valencia, Sandra C. ; Welton, E. Judd
Author_Institution :
Goddard Space Flight Center, NASA, Greenbelt, MD
Volume :
4
Issue :
3
fYear :
2007
fDate :
7/1/2007 12:00:00 AM
Firstpage :
456
Lastpage :
460
Abstract :
Pulsed lidars are commonly used to retrieve vertical distributions of cloud and aerosol layers. It is widely believed that lidar cloud retrievals (other than cloud base altitude) are limited to optically thin clouds. Here, we demonstrate that lidars can retrieve optical depths of thick clouds using solar background light as a signal, rather than (as now) merely a noise to be subtracted. Validations against other instruments show that retrieved cloud optical depths agree within 10%-15% for overcast stratus and broken clouds. In fact, for broken cloud situations, one can retrieve not only the aerosol properties in clear-sky periods using lidar signals, but also the optical depth of thick clouds in cloudy periods using solar background signals. This indicates that, in general, it may be possible to retrieve both aerosol and cloud properties using a single lidar. Thus, lidar observations have great untapped potential to study interactions between clouds and aerosols.
Keywords :
aerosols; clouds; geophysical signal processing; optical radar; sunlight; aerosol layer; cloud layer; cloud optical depth retrievals; micropulse lidars signals; solar background light; Aerosols; Background noise; Calibration; Clouds; Laser radar; NASA; Optical attenuators; Optical filters; Optical noise; Optical sensors; Cloud; cloud–aerosol interactions; lidar; remote sensing; zenith radiance;
fLanguage :
English
Journal_Title :
Geoscience and Remote Sensing Letters, IEEE
Publisher :
ieee
ISSN :
1545-598X
Type :
jour
DOI :
10.1109/LGRS.2007.896722
Filename :
4271445
Link To Document :
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