Additional global climate cooling by clouds due to ice crystal complexity
<p>Ice crystal submicron structures have a large impact on the optical properties of cirrus clouds and consequently on their radiative effect. Although there is growing evidence that atmospheric ice crystals are rarely pristine, direct in situ observations of the degree of ice crystal compl...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2018-11-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/18/15767/2018/acp-18-15767-2018.pdf |
| _version_ | 1817981127825031168 |
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| author | E. Järvinen E. Järvinen O. Jourdan D. Neubauer B. Yao C. Liu M. O. Andreae M. O. Andreae U. Lohmann M. Wendisch G. M. McFarquhar G. M. McFarquhar T. Leisner M. Schnaiter |
| author_facet | E. Järvinen E. Järvinen O. Jourdan D. Neubauer B. Yao C. Liu M. O. Andreae M. O. Andreae U. Lohmann M. Wendisch G. M. McFarquhar G. M. McFarquhar T. Leisner M. Schnaiter |
| author_sort | E. Järvinen |
| collection | DOAJ |
| description | <p>Ice crystal submicron structures have a large impact on the optical
properties of cirrus clouds and consequently on their radiative effect.
Although there is growing evidence that atmospheric ice crystals are rarely
pristine, direct in situ observations of the degree of ice crystal complexity
are largely missing. Here we show a comprehensive in situ data set of ice
crystal complexity coupled with measurements of the cloud angular scattering
functions collected during a number of observational airborne campaigns at
diverse geographical locations. Our results demonstrate that an overwhelming
fraction (between 61 % and 81 %) of atmospheric ice crystals sampled
in the different regions contain mesoscopic deformations and, as a
consequence, a similar flat and featureless angular scattering function is
observed. A comparison between the measurements and a database of optical
particle properties showed that severely roughened hexagonal aggregates
optimally represent the measurements in the observed angular range. Based on
this optical model, a new parameterization of the cloud bulk asymmetry factor
was introduced and its effects were tested in a global climate model. The
modelling results suggest that, due to ice crystal complexity, ice-containing
clouds can induce an additional short-wave cooling effect of
−1.12 W m<sup>2</sup> on the top-of-the-atmosphere radiative budget that has
not yet been considered.</p> |
| first_indexed | 2024-04-13T23:01:42Z |
| format | Article |
| id | doaj.art-689d9f392119447ea27fbf2bdc1c845f |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-04-13T23:01:42Z |
| publishDate | 2018-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-689d9f392119447ea27fbf2bdc1c845f2022-12-22T02:25:49ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242018-11-0118157671578110.5194/acp-18-15767-2018Additional global climate cooling by clouds due to ice crystal complexityE. Järvinen0E. Järvinen1O. Jourdan2D. Neubauer3B. Yao4C. Liu5M. O. Andreae6M. O. Andreae7U. Lohmann8M. Wendisch9G. M. McFarquhar10G. M. McFarquhar11T. Leisner12M. Schnaiter13Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research, Karlsruhe, Germanynow at: National Center for Atmospheric Research (NCAR), Boulder, CO, USALaboratoire de Météorologie Physique, Université Clermont Auvergne, OPGC, UMR/CNRS 6016, Clermont-Ferrand, FranceInstitute of Atmospheric and Climate Science, ETH Zürich, Zürich, SwitzerlandCollaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, ChinaCollaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, ChinaBiogeochemistry Department, Max Planck Institute for Chemistry, Mainz, GermanyScripps Institution of Oceanography, University of California San Diego, La Jolla, California, USAInstitute of Atmospheric and Climate Science, ETH Zürich, Zürich, SwitzerlandLeipzig Institute for Meteorology, University of Leipzig, Leipzig, GermanyCooperative Institute for Mesoscale Meteorological Studies, University of Oklahoma, Norman, OK, USASchool of Meteorology, University of Oklahoma, Norman, OK, USAKarlsruhe Institute of Technology, Institute of Meteorology and Climate Research, Karlsruhe, GermanyKarlsruhe Institute of Technology, Institute of Meteorology and Climate Research, Karlsruhe, Germany<p>Ice crystal submicron structures have a large impact on the optical properties of cirrus clouds and consequently on their radiative effect. Although there is growing evidence that atmospheric ice crystals are rarely pristine, direct in situ observations of the degree of ice crystal complexity are largely missing. Here we show a comprehensive in situ data set of ice crystal complexity coupled with measurements of the cloud angular scattering functions collected during a number of observational airborne campaigns at diverse geographical locations. Our results demonstrate that an overwhelming fraction (between 61 % and 81 %) of atmospheric ice crystals sampled in the different regions contain mesoscopic deformations and, as a consequence, a similar flat and featureless angular scattering function is observed. A comparison between the measurements and a database of optical particle properties showed that severely roughened hexagonal aggregates optimally represent the measurements in the observed angular range. Based on this optical model, a new parameterization of the cloud bulk asymmetry factor was introduced and its effects were tested in a global climate model. The modelling results suggest that, due to ice crystal complexity, ice-containing clouds can induce an additional short-wave cooling effect of −1.12 W m<sup>2</sup> on the top-of-the-atmosphere radiative budget that has not yet been considered.</p>https://www.atmos-chem-phys.net/18/15767/2018/acp-18-15767-2018.pdf |
| spellingShingle | E. Järvinen E. Järvinen O. Jourdan D. Neubauer B. Yao C. Liu M. O. Andreae M. O. Andreae U. Lohmann M. Wendisch G. M. McFarquhar G. M. McFarquhar T. Leisner M. Schnaiter Additional global climate cooling by clouds due to ice crystal complexity Atmospheric Chemistry and Physics |
| title | Additional global climate cooling by clouds due to ice crystal complexity |
| title_full | Additional global climate cooling by clouds due to ice crystal complexity |
| title_fullStr | Additional global climate cooling by clouds due to ice crystal complexity |
| title_full_unstemmed | Additional global climate cooling by clouds due to ice crystal complexity |
| title_short | Additional global climate cooling by clouds due to ice crystal complexity |
| title_sort | additional global climate cooling by clouds due to ice crystal complexity |
| url | https://www.atmos-chem-phys.net/18/15767/2018/acp-18-15767-2018.pdf |
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