Using CPL Data to Derive Optical Properties of Aerosols For
the CALIPSO Sa Selection Algorithm
Ali H. Omar1 and Tatyana Babakaeva2
NASA Langley research Center, Hampton, VA
Hampton University, Hampton, VA
Abstract
This study uses Cloud Physics Lidar (CPL) measurements during SAFARI –2000
[McGill et all., 2003] in South Africa and CRYSTAL-FACE off the coast of Florida.
CPL lidar measurements provide a database with measurements of color ratio
and depolarization ratio, optical depth and ATB layer measurements. Using all
these measurements separation of cloud layers from aerosol layers is
accomplished first, then classification of aerosol layers is achieved by the cluster
analysis technique.
We represent the probability distributions functions (PDFs) of depolarization ratio,
the color ratio of the backscatter at 1064nm to 532nm for each cluster and then
we estimate the aerosol type of each cluster using all available information. We
present the distribution of these lidar observable optical properties for desert
dust, biomass burning and marine aerosols.
The results of the aerosol clusters are verified and compared by using air-borne
in situ measurements, ground-based measurement and the MOderate Resolution
Imaging Spectrometer (MODIS) data as the combination of multiple data tools.
References
McGill, M.J., W.D. Hlavka, W.D. Hart, E.J. Welton, and J.R.Campbell, Airborne
lidar measurements of aerosol optical properties during SAFARI-2000,
J.Geophys. Res.,108 (D13)
Kaufman, L., and P.J. Rousseeuw, Finding Groups in Data, John W iley and
Sons, New York, 1990
Vaughan et al. SIBYL: A Selected Iterated Boundary Location Algorithm for
Finding Cloud and Aerosol Layers in CALIPSO Lidar Data, in Lidar Remote
Sensing in Atmospheric and Earth Sciences, Québec, Canada, 2002