Cirrus Clouds
The goal of this chapter is to synthesize information about what is now known about one of the three main types of clouds, cirrus, and to identify areas where more knowledge is needed. Cirrus clouds, composed of ice particles, form in the upper troposphere, where temperatures are generally below −30...
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American Meteorological Society
2018
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| Länkar: | http://hdl.handle.net/1721.1/118399 https://orcid.org/0000-0003-1851-8740 |
| _version_ | 1826204773273042944 |
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| author | Heymsfield, Andrew J. Krämer, Martina Luebke, Anna Brown, Phil Franklin, Charmaine Lawson, Paul Lohmann, Ulrike McFarquhar, Greg Ulanowski, Zbigniew Van Tricht, Kristof Cziczo, Daniel James |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Heymsfield, Andrew J. Krämer, Martina Luebke, Anna Brown, Phil Franklin, Charmaine Lawson, Paul Lohmann, Ulrike McFarquhar, Greg Ulanowski, Zbigniew Van Tricht, Kristof Cziczo, Daniel James |
| author_sort | Heymsfield, Andrew J. |
| collection | MIT |
| description | The goal of this chapter is to synthesize information about what is now known about one of the three main types of clouds, cirrus, and to identify areas where more knowledge is needed. Cirrus clouds, composed of ice particles, form in the upper troposphere, where temperatures are generally below −30°C. Satellite observations show that the maximum-occurrence frequency of cirrus is near the tropics, with a large latitudinal movement seasonally. In situ measurements obtained over a wide range of cirrus types, formation mechanisms, temperatures, and geographical locations indicate that the ice water content and particle size generally decrease with decreasing temperature, whereas the ice particle concentration is nearly constant or increases slightly with decreasing temperature. High ice concentrations, sometimes observed in strong updrafts, result from homogeneous nucleation. The satellite-based and in situ measurements indicate that cirrus ice crystals typically differ from the simple, idealized geometry for smooth hexagonal shapes, indicating complexity and/or surface roughness. Their shapes significantly impact cirrus radiative properties and feedbacks to climate. Cirrus clouds, one of the most uncertain components of general circulation models (GCM), pose one of the greatest challenges in predicting the rate and geographical pattern of climate change. Improved measurements of the properties and size distributions and surface structure of small ice crystals (about 20 μm) and identifying the dominant ice nucleation process (heterogeneous versus homogeneous ice nucleation) under different cloud dynamical forcings will lead to a better representation of their properties in GCM and in modeling their current and future effects on climate. |
| first_indexed | 2024-09-23T13:01:10Z |
| format | Article |
| id | mit-1721.1/118399 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T13:01:10Z |
| publishDate | 2018 |
| publisher | American Meteorological Society |
| record_format | dspace |
| spelling | mit-1721.1/1183992022-10-01T12:33:45Z Cirrus Clouds Heymsfield, Andrew J. Krämer, Martina Luebke, Anna Brown, Phil Franklin, Charmaine Lawson, Paul Lohmann, Ulrike McFarquhar, Greg Ulanowski, Zbigniew Van Tricht, Kristof Cziczo, Daniel James Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Cziczo, Daniel James The goal of this chapter is to synthesize information about what is now known about one of the three main types of clouds, cirrus, and to identify areas where more knowledge is needed. Cirrus clouds, composed of ice particles, form in the upper troposphere, where temperatures are generally below −30°C. Satellite observations show that the maximum-occurrence frequency of cirrus is near the tropics, with a large latitudinal movement seasonally. In situ measurements obtained over a wide range of cirrus types, formation mechanisms, temperatures, and geographical locations indicate that the ice water content and particle size generally decrease with decreasing temperature, whereas the ice particle concentration is nearly constant or increases slightly with decreasing temperature. High ice concentrations, sometimes observed in strong updrafts, result from homogeneous nucleation. The satellite-based and in situ measurements indicate that cirrus ice crystals typically differ from the simple, idealized geometry for smooth hexagonal shapes, indicating complexity and/or surface roughness. Their shapes significantly impact cirrus radiative properties and feedbacks to climate. Cirrus clouds, one of the most uncertain components of general circulation models (GCM), pose one of the greatest challenges in predicting the rate and geographical pattern of climate change. Improved measurements of the properties and size distributions and surface structure of small ice crystals (about 20 μm) and identifying the dominant ice nucleation process (heterogeneous versus homogeneous ice nucleation) under different cloud dynamical forcings will lead to a better representation of their properties in GCM and in modeling their current and future effects on climate. 2018-10-09T18:49:27Z 2018-10-09T18:49:27Z 2017-01 2018-09-20T18:22:47Z Article http://purl.org/eprint/type/JournalArticle 0065-9401 http://hdl.handle.net/1721.1/118399 Heymsfield, Andrew J. et al. “Cirrus Clouds.” Meteorological Monographs 58 (January 2017): 2.1–2.26 © 2017 American Meteorological Society https://orcid.org/0000-0003-1851-8740 http://dx.doi.org/10.1175/AMSMONOGRAPHS-D-16-0010.1 Meteorological Monographs Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Meteorological Society American Meteorological Society |
| spellingShingle | Heymsfield, Andrew J. Krämer, Martina Luebke, Anna Brown, Phil Franklin, Charmaine Lawson, Paul Lohmann, Ulrike McFarquhar, Greg Ulanowski, Zbigniew Van Tricht, Kristof Cziczo, Daniel James Cirrus Clouds |
| title | Cirrus Clouds |
| title_full | Cirrus Clouds |
| title_fullStr | Cirrus Clouds |
| title_full_unstemmed | Cirrus Clouds |
| title_short | Cirrus Clouds |
| title_sort | cirrus clouds |
| url | http://hdl.handle.net/1721.1/118399 https://orcid.org/0000-0003-1851-8740 |
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