CALIPSO observations of the dependence of homo- and heterogeneous ice nucleation in cirrus clouds on latitude, season and surface condition
There are two fundamental mechanisms through which cirrus clouds form; homo- and heterogeneous ice nucleation (henceforth hom and het). The relative contribution of each mechanism to ice crystal production often determines the microphysical and radiative properties of a cirrus cloud. A new satellite...
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ftcopernicus:oai:publications.copernicus.org:acpd56092 2023-05-15T13:43:08+02:00 CALIPSO observations of the dependence of homo- and heterogeneous ice nucleation in cirrus clouds on latitude, season and surface condition Mitchell, David L. Garnier, Anne Avery, Melody Erfani, Ehsan 2018-08-10 application/pdf https://doi.org/10.5194/acp-2016-1062 https://www.atmos-chem-phys-discuss.net/acp-2016-1062/ eng eng doi:10.5194/acp-2016-1062 https://www.atmos-chem-phys-discuss.net/acp-2016-1062/ eISSN: 1680-7324 Text 2018 ftcopernicus https://doi.org/10.5194/acp-2016-1062 2019-12-24T09:51:47Z There are two fundamental mechanisms through which cirrus clouds form; homo- and heterogeneous ice nucleation (henceforth hom and het). The relative contribution of each mechanism to ice crystal production often determines the microphysical and radiative properties of a cirrus cloud. A new satellite remote sensing method is described in this study to estimate cirrus cloud ice particle number concentration and the relative contribution of hom and het to cirrus cloud formation as a function of altitude, latitude, season and surface type (e.g. land vs. ocean). This method uses co-located observations from the Infrared Imaging Radiometer (IIR) and from the CALIOP ( Cloud and Aerosol Lidar with Orthogonal Polarization ) lidar aboard the CALIPSO ( Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation ) polar orbiting satellite, employing IIR channels at 10.6 μm and 12.05 μm. The method is applied here to single-layered clouds of visible optical depth between about 0.3 and 3. Two years of Version 3 data have been analyzed for the years 2008 and 2013, with each season characterized in terms of 532 nm cirrus cloud centroid altitude and temperature, the cirrus cloud ice particle number concentration, effective diameter, layer-average ice water content and visible optical depth. Using a conservative criterion for hom cirrus, on average, the sampled cirrus clouds formed through hom occur about 43 % of the time in the Arctic and 50 % of the time in the Antarctic, and during winter at mid-latitudes in the Northern Hemisphere, hom cirrus occur 37 % of the time. Elsewhere (and during other seasons in the Northern Hemisphere mid-latitudes), this hom cirrus fraction is lower. Processes that could potentially explain these observations are discussed, as well as the potential relevancy of these results to ice nucleation studies, climate modeling and jet-stream dynamics. Text Antarc* Antarctic Arctic Copernicus Publications: E-Journals Antarctic Arctic The Antarctic |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
There are two fundamental mechanisms through which cirrus clouds form; homo- and heterogeneous ice nucleation (henceforth hom and het). The relative contribution of each mechanism to ice crystal production often determines the microphysical and radiative properties of a cirrus cloud. A new satellite remote sensing method is described in this study to estimate cirrus cloud ice particle number concentration and the relative contribution of hom and het to cirrus cloud formation as a function of altitude, latitude, season and surface type (e.g. land vs. ocean). This method uses co-located observations from the Infrared Imaging Radiometer (IIR) and from the CALIOP ( Cloud and Aerosol Lidar with Orthogonal Polarization ) lidar aboard the CALIPSO ( Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation ) polar orbiting satellite, employing IIR channels at 10.6 μm and 12.05 μm. The method is applied here to single-layered clouds of visible optical depth between about 0.3 and 3. Two years of Version 3 data have been analyzed for the years 2008 and 2013, with each season characterized in terms of 532 nm cirrus cloud centroid altitude and temperature, the cirrus cloud ice particle number concentration, effective diameter, layer-average ice water content and visible optical depth. Using a conservative criterion for hom cirrus, on average, the sampled cirrus clouds formed through hom occur about 43 % of the time in the Arctic and 50 % of the time in the Antarctic, and during winter at mid-latitudes in the Northern Hemisphere, hom cirrus occur 37 % of the time. Elsewhere (and during other seasons in the Northern Hemisphere mid-latitudes), this hom cirrus fraction is lower. Processes that could potentially explain these observations are discussed, as well as the potential relevancy of these results to ice nucleation studies, climate modeling and jet-stream dynamics. |
format |
Text |
author |
Mitchell, David L. Garnier, Anne Avery, Melody Erfani, Ehsan |
spellingShingle |
Mitchell, David L. Garnier, Anne Avery, Melody Erfani, Ehsan CALIPSO observations of the dependence of homo- and heterogeneous ice nucleation in cirrus clouds on latitude, season and surface condition |
author_facet |
Mitchell, David L. Garnier, Anne Avery, Melody Erfani, Ehsan |
author_sort |
Mitchell, David L. |
title |
CALIPSO observations of the dependence of homo- and heterogeneous ice nucleation in cirrus clouds on latitude, season and surface condition |
title_short |
CALIPSO observations of the dependence of homo- and heterogeneous ice nucleation in cirrus clouds on latitude, season and surface condition |
title_full |
CALIPSO observations of the dependence of homo- and heterogeneous ice nucleation in cirrus clouds on latitude, season and surface condition |
title_fullStr |
CALIPSO observations of the dependence of homo- and heterogeneous ice nucleation in cirrus clouds on latitude, season and surface condition |
title_full_unstemmed |
CALIPSO observations of the dependence of homo- and heterogeneous ice nucleation in cirrus clouds on latitude, season and surface condition |
title_sort |
calipso observations of the dependence of homo- and heterogeneous ice nucleation in cirrus clouds on latitude, season and surface condition |
publishDate |
2018 |
url |
https://doi.org/10.5194/acp-2016-1062 https://www.atmos-chem-phys-discuss.net/acp-2016-1062/ |
geographic |
Antarctic Arctic The Antarctic |
geographic_facet |
Antarctic Arctic The Antarctic |
genre |
Antarc* Antarctic Arctic |
genre_facet |
Antarc* Antarctic Arctic |
op_source |
eISSN: 1680-7324 |
op_relation |
doi:10.5194/acp-2016-1062 https://www.atmos-chem-phys-discuss.net/acp-2016-1062/ |
op_doi |
https://doi.org/10.5194/acp-2016-1062 |
_version_ |
1766185174744170496 |