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constrained cirrus cloud retrievals

Posted: Tue Nov 12, 2019 8:25 am America/New_York
by EarthdataForumContributor
What are 'constrained cirrus cloud retrievals', how do I find them, and why should I bother to look for them?

Re: constrained cirrus cloud retrievals

Posted: Tue Nov 12, 2019 8:28 am America/New_York
by EarthdataForumContributor
Thank you for posting in the Earthdata Forum. A subject expert has been contacted to review your inquiry. We will be back with an answer as soon as possible.

Re: constrained cirrus cloud retrievals

Posted: Tue Nov 12, 2019 8:35 am America/New_York
by EarthdataForumContributor
Posted on behalf of ASDC CALIPSO SME

Constrained cirrus cloud retrievals are those cirrus cloud cases where it was possible to measure the backscatter molecular return below the cirrus cloud in a 'clear air' region and obtain a direct measurement of the cirrus cloud two-way transmittance or optical depth. This measured transmittance is then used to constrain the retrieval of the extinction profile of the cloud, thus reducing the uncertainty from using a default lidar ratio. These so-called constrained cirrus cloud retrievals are generally the highest quality retrievals of extinction provided by the lidar level 2 processing software.

The Extinction_QC_Flag_532, and Extinction_QC_Flag_1064 data sets will have bit field 1 set for constrained retrievals. These data sets can be found the 5 km layer products and bin-by-bin in the 5 km profile products.