Direct estimation of the global distribution of vertical velocity within cirrus clouds
Cirrus clouds determine the radiative balance of the upper troposphere and the transport of water vapor across the tropopause. The representation of vertical wind velocity, W, in atmospheric models constitutes the largest source of uncertainty in the calculation of the cirrus formation rate. Using g...
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ftleibnizopen:oai:oai.leibnizopen.de:X7u3IJEBBwLIz6xG4TLn 2024-09-09T19:23:19+00:00 Direct estimation of the global distribution of vertical velocity within cirrus clouds Barahona, Donifan Molod, Andrea Kalesse, Heike 2017 application/pdf https://oa.tib.eu/renate/handle/123456789/12123 https://doi.org/10.34657/11157 eng eng London : Nature Publishing Group CC BY 4.0 Unported https://creativecommons.org/licenses/by/4.0 500 600 Arctic calculation crystal simulation thermodynamics troposphere uncertainty velocity water transport water vapor Article Text 2017 ftleibnizopen https://doi.org/10.34657/11157 2024-08-05T12:41:55Z Cirrus clouds determine the radiative balance of the upper troposphere and the transport of water vapor across the tropopause. The representation of vertical wind velocity, W, in atmospheric models constitutes the largest source of uncertainty in the calculation of the cirrus formation rate. Using global atmospheric simulations with a spatial resolution of 7 km we obtain for the first time a direct estimate of the distribution of W at the scale relevant for cirrus formation, validated against long-term observations at two different ground sites. The standard deviation in W, σ w, varies widely over the globe with the highest values resulting from orographic uplift and convection, and the lowest occurring in the Arctic. Globally about 90% of the simulated σ w values are below 0.1 m s-1 and about one in 104 cloud formation events occur in environments with σ w > 0.8 m s-1. Combining our estimate with reanalysis products and an advanced cloud formation scheme results in lower homogeneous ice nucleation frequency than previously reported, and a decreasing average ice crystal concentration with decreasing temperature. These features are in agreement with observations and suggest that the correct parameterization of σ w is critical to simulate realistic cirrus properties. publishedVersion Article in Journal/Newspaper Arctic LeibnizOpen (The Leibniz Association) Arctic |
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Open Polar |
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LeibnizOpen (The Leibniz Association) |
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ftleibnizopen |
language |
English |
topic |
500 600 Arctic calculation crystal simulation thermodynamics troposphere uncertainty velocity water transport water vapor |
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500 600 Arctic calculation crystal simulation thermodynamics troposphere uncertainty velocity water transport water vapor Barahona, Donifan Molod, Andrea Kalesse, Heike Direct estimation of the global distribution of vertical velocity within cirrus clouds |
topic_facet |
500 600 Arctic calculation crystal simulation thermodynamics troposphere uncertainty velocity water transport water vapor |
description |
Cirrus clouds determine the radiative balance of the upper troposphere and the transport of water vapor across the tropopause. The representation of vertical wind velocity, W, in atmospheric models constitutes the largest source of uncertainty in the calculation of the cirrus formation rate. Using global atmospheric simulations with a spatial resolution of 7 km we obtain for the first time a direct estimate of the distribution of W at the scale relevant for cirrus formation, validated against long-term observations at two different ground sites. The standard deviation in W, σ w, varies widely over the globe with the highest values resulting from orographic uplift and convection, and the lowest occurring in the Arctic. Globally about 90% of the simulated σ w values are below 0.1 m s-1 and about one in 104 cloud formation events occur in environments with σ w > 0.8 m s-1. Combining our estimate with reanalysis products and an advanced cloud formation scheme results in lower homogeneous ice nucleation frequency than previously reported, and a decreasing average ice crystal concentration with decreasing temperature. These features are in agreement with observations and suggest that the correct parameterization of σ w is critical to simulate realistic cirrus properties. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Barahona, Donifan Molod, Andrea Kalesse, Heike |
author_facet |
Barahona, Donifan Molod, Andrea Kalesse, Heike |
author_sort |
Barahona, Donifan |
title |
Direct estimation of the global distribution of vertical velocity within cirrus clouds |
title_short |
Direct estimation of the global distribution of vertical velocity within cirrus clouds |
title_full |
Direct estimation of the global distribution of vertical velocity within cirrus clouds |
title_fullStr |
Direct estimation of the global distribution of vertical velocity within cirrus clouds |
title_full_unstemmed |
Direct estimation of the global distribution of vertical velocity within cirrus clouds |
title_sort |
direct estimation of the global distribution of vertical velocity within cirrus clouds |
publisher |
London : Nature Publishing Group |
publishDate |
2017 |
url |
https://oa.tib.eu/renate/handle/123456789/12123 https://doi.org/10.34657/11157 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_rights |
CC BY 4.0 Unported https://creativecommons.org/licenses/by/4.0 |
op_doi |
https://doi.org/10.34657/11157 |
_version_ |
1809763721925361664 |