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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ftdoajarticles:oai:doaj.org/article:3e73fdceabbf47a78d5de690fdc327ef 2024-01-07T09:39:35+01:00 Characterizing the near-global cloud vertical structures over land using high-resolution radiosonde measurements H. Xu J. Guo B. Tong J. Zhang T. Chen X. Guo W. Chen 2023-12-01T00:00:00Z https://doi.org/10.5194/acp-23-15011-2023 https://doaj.org/article/3e73fdceabbf47a78d5de690fdc327ef EN eng Copernicus Publications https://acp.copernicus.org/articles/23/15011/2023/acp-23-15011-2023.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-23-15011-2023 1680-7316 1680-7324 https://doaj.org/article/3e73fdceabbf47a78d5de690fdc327ef Atmospheric Chemistry and Physics, Vol 23, Pp 15011-15038 (2023) Physics QC1-999 Chemistry QD1-999 article 2023 ftdoajarticles https://doi.org/10.5194/acp-23-15011-2023 2023-12-10T01:40:08Z 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, ... Article in Journal/Newspaper Antarc* Antarctica Directory of Open Access Journals: DOAJ Articles Pacific Atmospheric Chemistry and Physics 23 23 15011 15038 |
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Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Physics QC1-999 Chemistry QD1-999 |
spellingShingle |
Physics QC1-999 Chemistry QD1-999 H. Xu J. Guo B. Tong J. Zhang T. Chen X. Guo W. Chen Characterizing the near-global cloud vertical structures over land using high-resolution radiosonde measurements |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
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 |
Article in Journal/Newspaper |
author |
H. Xu J. Guo B. Tong J. Zhang T. Chen X. Guo W. Chen |
author_facet |
H. Xu J. Guo B. Tong J. Zhang T. Chen X. Guo W. Chen |
author_sort |
H. Xu |
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 |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/acp-23-15011-2023 https://doaj.org/article/3e73fdceabbf47a78d5de690fdc327ef |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
Atmospheric Chemistry and Physics, Vol 23, Pp 15011-15038 (2023) |
op_relation |
https://acp.copernicus.org/articles/23/15011/2023/acp-23-15011-2023.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-23-15011-2023 1680-7316 1680-7324 https://doaj.org/article/3e73fdceabbf47a78d5de690fdc327ef |
op_doi |
https://doi.org/10.5194/acp-23-15011-2023 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
23 |
container_issue |
23 |
container_start_page |
15011 |
op_container_end_page |
15038 |
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1787429788535750656 |