Characterizing the near-global cloud vertical structures over land using high-resolution radiosonde measurements
Cloud remains one of the largest uncertainties in weather and climate research due to the lack of fine-resolution observations of cloud vertical structure (CVS) on a large scale. In this study, near-global CVS is characterized by high-vertical-resolution twice-daily radiosonde observations from 374...
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ftcopernicus:oai:publications.copernicus.org:egusphere110190 2024-01-07T09:38:54+01:00 Characterizing the near-global cloud vertical structures over land using high-resolution radiosonde measurements Xu, Hui Guo, Jianping Tong, Bing Zhang, Jinqiang Chen, Tianmeng Guo, Xiaoran Zhang, Jian Chen, Wenqing 2023-12-06 application/pdf https://doi.org/10.5194/egusphere-2023-472 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-472/ eng eng doi:10.5194/egusphere-2023-472 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-472/ eISSN: Text 2023 ftcopernicus https://doi.org/10.5194/egusphere-2023-472 2023-12-11T17:24:19Z Cloud remains one of the largest uncertainties in weather and climate research due to the lack of fine-resolution observations of cloud vertical structure (CVS) on a large scale. In this study, near-global CVS is characterized by high-vertical-resolution twice-daily radiosonde observations from 374 stations over land, which are distributed in Europe, North America, East Asia, Australia, the Pacific Ocean, and Antarctica. To this end, we initially develop a novel method to determine CVS, by combining both the vertical gradients of air temperature and relative humidity (RH) and the altitude-dependent thresholds of RH. It is found that the cloud base heights (CBHs) from radiosondes have a higher correlation coefficient ( R = 0.91) with the CBHs from a millimeter-wave cloud radar than those from the ERA5 reanalysis ( R = 0.49). Overall, cloudy skies occur 65.3 % (69.5 %) of the time, of which 55.4 % (53.8 %) are one-layer clouds at 00:00 (12:00) UTC. Most multi-layer clouds are two-layer clouds, accounting for 62.2 % (61.1 %) among multi-layer clouds at 00:00 (12:00) UTC. Geographically, one-layer clouds tend to occur over arid regions, whereas two-layer clouds do not show any clear spatial preference. The cloud bases and tops over arid regions are higher compared with humid regions albeit with smaller cloud thickness (CT). Clouds tend to have lower bases and thinner layer thicknesses as the number of cloud layer increases. The global-mean CT, CBH, and cloud top height (CTH) are 4.89 ± 1.36 (5.37 ± 1.58), 3.15 ± 1.15 (3.07 ± 1.06), and 8.04 ± 1.60 (8.44 ± 1.52) km above ground level (a.g.l.) at 00:00 (12:00) UTC, respectively. The occurrence frequency of clouds is bimodal, with lower peaks between 0.5 and 3 km a.g.l. and upper peaks between 6 and 10 km a.g.l. The CBH, CTH, and CT undergo almost the same seasonality; namely, their magnitudes in boreal summer are greater than in boreal winter. As expected, the occurrence frequencies of clouds exhibit pronounced diurnal cycles in different seasons. In boreal summer, ... Text Antarc* Antarctica Copernicus Publications: E-Journals Pacific |
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Copernicus Publications: E-Journals |
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English |
description |
Cloud remains one of the largest uncertainties in weather and climate research due to the lack of fine-resolution observations of cloud vertical structure (CVS) on a large scale. In this study, near-global CVS is characterized by high-vertical-resolution twice-daily radiosonde observations from 374 stations over land, which are distributed in Europe, North America, East Asia, Australia, the Pacific Ocean, and Antarctica. To this end, we initially develop a novel method to determine CVS, by combining both the vertical gradients of air temperature and relative humidity (RH) and the altitude-dependent thresholds of RH. It is found that the cloud base heights (CBHs) from radiosondes have a higher correlation coefficient ( R = 0.91) with the CBHs from a millimeter-wave cloud radar than those from the ERA5 reanalysis ( R = 0.49). Overall, cloudy skies occur 65.3 % (69.5 %) of the time, of which 55.4 % (53.8 %) are one-layer clouds at 00:00 (12:00) UTC. Most multi-layer clouds are two-layer clouds, accounting for 62.2 % (61.1 %) among multi-layer clouds at 00:00 (12:00) UTC. Geographically, one-layer clouds tend to occur over arid regions, whereas two-layer clouds do not show any clear spatial preference. The cloud bases and tops over arid regions are higher compared with humid regions albeit with smaller cloud thickness (CT). Clouds tend to have lower bases and thinner layer thicknesses as the number of cloud layer increases. The global-mean CT, CBH, and cloud top height (CTH) are 4.89 ± 1.36 (5.37 ± 1.58), 3.15 ± 1.15 (3.07 ± 1.06), and 8.04 ± 1.60 (8.44 ± 1.52) km above ground level (a.g.l.) at 00:00 (12:00) UTC, respectively. The occurrence frequency of clouds is bimodal, with lower peaks between 0.5 and 3 km a.g.l. and upper peaks between 6 and 10 km a.g.l. The CBH, CTH, and CT undergo almost the same seasonality; namely, their magnitudes in boreal summer are greater than in boreal winter. As expected, the occurrence frequencies of clouds exhibit pronounced diurnal cycles in different seasons. In boreal summer, ... |
format |
Text |
author |
Xu, Hui Guo, Jianping Tong, Bing Zhang, Jinqiang Chen, Tianmeng Guo, Xiaoran Zhang, Jian Chen, Wenqing |
spellingShingle |
Xu, Hui Guo, Jianping Tong, Bing Zhang, Jinqiang Chen, Tianmeng Guo, Xiaoran Zhang, Jian Chen, Wenqing Characterizing the near-global cloud vertical structures over land using high-resolution radiosonde measurements |
author_facet |
Xu, Hui Guo, Jianping Tong, Bing Zhang, Jinqiang Chen, Tianmeng Guo, Xiaoran Zhang, Jian Chen, Wenqing |
author_sort |
Xu, Hui |
title |
Characterizing the near-global cloud vertical structures over land using high-resolution radiosonde measurements |
title_short |
Characterizing the near-global cloud vertical structures over land using high-resolution radiosonde measurements |
title_full |
Characterizing the near-global cloud vertical structures over land using high-resolution radiosonde measurements |
title_fullStr |
Characterizing the near-global cloud vertical structures over land using high-resolution radiosonde measurements |
title_full_unstemmed |
Characterizing the near-global cloud vertical structures over land using high-resolution radiosonde measurements |
title_sort |
characterizing the near-global cloud vertical structures over land using high-resolution radiosonde measurements |
publishDate |
2023 |
url |
https://doi.org/10.5194/egusphere-2023-472 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-472/ |
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Pacific |
geographic_facet |
Pacific |
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Antarc* Antarctica |
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Antarc* Antarctica |
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eISSN: |
op_relation |
doi:10.5194/egusphere-2023-472 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-472/ |
op_doi |
https://doi.org/10.5194/egusphere-2023-472 |
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1787426875368275968 |