Surface matters: limitations of CALIPSO V3 aerosol typing in coastal regions

In the CALIPSO data analysis, surface type (land/ocean) is used to augment the aerosol characterization. However, this surface-dependent aerosol typing prohibits a correct classification of marine aerosol over land that is advected from ocean to land. This might result in a systematic overestimation...

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Main Authors: T. Kanitz, A. Ansmann, A. Foth, P. Seifert, U. Wandinger, R. Engelmann, H. Baars, D. Althausen, C. Casiccia, F. Zamorano
Format: Article
Language:English
Published: Copernicus Publications 2014-07-01
Series:Atmospheric Measurement Techniques
Online Access:http://www.atmos-meas-tech.net/7/2061/2014/amt-7-2061-2014.pdf
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author T. Kanitz
A. Ansmann
A. Foth
P. Seifert
U. Wandinger
R. Engelmann
H. Baars
D. Althausen
C. Casiccia
F. Zamorano
author_facet T. Kanitz
A. Ansmann
A. Foth
P. Seifert
U. Wandinger
R. Engelmann
H. Baars
D. Althausen
C. Casiccia
F. Zamorano
author_sort T. Kanitz
collection DOAJ
description In the CALIPSO data analysis, surface type (land/ocean) is used to augment the aerosol characterization. However, this surface-dependent aerosol typing prohibits a correct classification of marine aerosol over land that is advected from ocean to land. This might result in a systematic overestimation of the particle extinction coefficient and of the aerosol optical thickness (AOT) of up to a factor of 3.5 over land in coastal areas. We present a long-term comparison of CALIPSO and ground-based lidar observations of the aerosol conditions in the coastal environment of southern South America (Punta Arenas, Chile, 53° S), performed in December 2009–April 2010. Punta Arenas is almost entirely influenced by marine particles throughout the year, indicated by a rather low AOT of 0.02–0.04. However, we found an unexpectedly high fraction of continental aerosol in the aerosol types inferred by means of CALIOP observations and, correspondingly, too high values of particle extinction. Similar features of the CALIOP data analysis are presented for four other coastal areas around the world. Since CALIOP data serve as important input for global climate models, the influence of this systematic error was estimated by means of simplified radiative-transfer calculations.
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spelling doaj.art-cacf159b2f7a4911a64ac4702beb000d2022-12-22T02:44:41ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482014-07-01772061207210.5194/amt-7-2061-2014Surface matters: limitations of CALIPSO V3 aerosol typing in coastal regionsT. Kanitz0A. Ansmann1A. Foth2P. Seifert3U. Wandinger4R. Engelmann5H. Baars6D. Althausen7C. Casiccia8F. Zamorano9Leibniz Institute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig, GermanyLeibniz Institute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig, GermanyLeipzig Institute for Meteorology, University of Leipzig, Stephanstr. 3, 04103 Leipzig, GermanyLeibniz Institute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig, GermanyLeibniz Institute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig, GermanyLeibniz Institute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig, GermanyLeibniz Institute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig, GermanyLeibniz Institute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig, GermanyOzone and RUV Laboratory, Universidad de Magallanes, Punta Arenas 6210427, ChileOzone and RUV Laboratory, Universidad de Magallanes, Punta Arenas 6210427, ChileIn the CALIPSO data analysis, surface type (land/ocean) is used to augment the aerosol characterization. However, this surface-dependent aerosol typing prohibits a correct classification of marine aerosol over land that is advected from ocean to land. This might result in a systematic overestimation of the particle extinction coefficient and of the aerosol optical thickness (AOT) of up to a factor of 3.5 over land in coastal areas. We present a long-term comparison of CALIPSO and ground-based lidar observations of the aerosol conditions in the coastal environment of southern South America (Punta Arenas, Chile, 53° S), performed in December 2009–April 2010. Punta Arenas is almost entirely influenced by marine particles throughout the year, indicated by a rather low AOT of 0.02–0.04. However, we found an unexpectedly high fraction of continental aerosol in the aerosol types inferred by means of CALIOP observations and, correspondingly, too high values of particle extinction. Similar features of the CALIOP data analysis are presented for four other coastal areas around the world. Since CALIOP data serve as important input for global climate models, the influence of this systematic error was estimated by means of simplified radiative-transfer calculations.http://www.atmos-meas-tech.net/7/2061/2014/amt-7-2061-2014.pdf
spellingShingle T. Kanitz
A. Ansmann
A. Foth
P. Seifert
U. Wandinger
R. Engelmann
H. Baars
D. Althausen
C. Casiccia
F. Zamorano
Surface matters: limitations of CALIPSO V3 aerosol typing in coastal regions
Atmospheric Measurement Techniques
title Surface matters: limitations of CALIPSO V3 aerosol typing in coastal regions
title_full Surface matters: limitations of CALIPSO V3 aerosol typing in coastal regions
title_fullStr Surface matters: limitations of CALIPSO V3 aerosol typing in coastal regions
title_full_unstemmed Surface matters: limitations of CALIPSO V3 aerosol typing in coastal regions
title_short Surface matters: limitations of CALIPSO V3 aerosol typing in coastal regions
title_sort surface matters limitations of calipso v3 aerosol typing in coastal regions
url http://www.atmos-meas-tech.net/7/2061/2014/amt-7-2061-2014.pdf
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