Large-eddy simulation of a two-layer boundary-layer cloud system from the Arctic Ocean 2018 expedition
Climate change is particularly noticeable in the Arctic. The most common type of cloud at these latitudes is mixed-phase stratocumulus. These clouds occur frequently and persistently during all seasons and play a critical role in the Arctic energy budget. Previous observations in the central (north...
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ftdoajarticles:oai:doaj.org/article:760fcde143bb4b24aa0761097a0a921e 2023-07-23T04:17:20+02:00 Large-eddy simulation of a two-layer boundary-layer cloud system from the Arctic Ocean 2018 expedition I. Bulatovic J. Savre M. Tjernström C. Leck A. M. L. Ekman 2023-06-01T00:00:00Z https://doi.org/10.5194/acp-23-7033-2023 https://doaj.org/article/760fcde143bb4b24aa0761097a0a921e EN eng Copernicus Publications https://acp.copernicus.org/articles/23/7033/2023/acp-23-7033-2023.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-23-7033-2023 1680-7316 1680-7324 https://doaj.org/article/760fcde143bb4b24aa0761097a0a921e Atmospheric Chemistry and Physics, Vol 23, Pp 7033-7055 (2023) Physics QC1-999 Chemistry QD1-999 article 2023 ftdoajarticles https://doi.org/10.5194/acp-23-7033-2023 2023-07-02T00:39:55Z Climate change is particularly noticeable in the Arctic. The most common type of cloud at these latitudes is mixed-phase stratocumulus. These clouds occur frequently and persistently during all seasons and play a critical role in the Arctic energy budget. Previous observations in the central (north of 80 ∘ N) Arctic have shown a high occurrence of prolonged periods of a shallow, single-layer mixed-phase stratocumulus at the top of the boundary layer (BL; altitudes ∼ 300 to 400 m). However, recent observations from the summer of 2018 instead showed a prevalence of a two-layer boundary-layer cloud system. Here we use large-eddy simulation to examine the maintenance of one of the cloud systems observed in the summer of 2018 and the sensitivity of the cloud layers to different micro- and macro-scale parameters. We find that the model generally reproduces the observed thermodynamic structure well, with two near-neutrally stratified layers in the BL caused by a low cloud (located within the first few hundred meters) capped by a lower-altitude temperature inversion and an upper cloud layer (based around one kilometer or slightly higher) capped by the main temperature inversion of the BL. The simulated cloud structure is persistent unless there are low aerosol number concentrations ( ≤ 5 cm −3 ), which cause the upper cloud layer to dissipate, or high large-scale wind speeds ( ≥ 8.5 m s −1 ) , which erode the lower inversion and the related cloud layer. The changes in cloud structure alter both the short- and longwave cloud radiative effect at the surface. This results in changes in the net radiative effect of the modeled cloud system, which can impact the surface melting or freezing. The findings highlight the importance of better understanding and representing aerosol sources and sinks over the central Arctic Ocean. Furthermore, they underline the significance of meteorological parameters, such as the large-scale wind speed, for maintaining the two-layer boundary-layer cloud structure encountered in the lower ... Article in Journal/Newspaper Arctic Arctic Ocean Climate change Directory of Open Access Journals: DOAJ Articles Arctic Arctic Ocean Atmospheric Chemistry and Physics 23 12 7033 7055 |
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Open Polar |
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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 I. Bulatovic J. Savre M. Tjernström C. Leck A. M. L. Ekman Large-eddy simulation of a two-layer boundary-layer cloud system from the Arctic Ocean 2018 expedition |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
Climate change is particularly noticeable in the Arctic. The most common type of cloud at these latitudes is mixed-phase stratocumulus. These clouds occur frequently and persistently during all seasons and play a critical role in the Arctic energy budget. Previous observations in the central (north of 80 ∘ N) Arctic have shown a high occurrence of prolonged periods of a shallow, single-layer mixed-phase stratocumulus at the top of the boundary layer (BL; altitudes ∼ 300 to 400 m). However, recent observations from the summer of 2018 instead showed a prevalence of a two-layer boundary-layer cloud system. Here we use large-eddy simulation to examine the maintenance of one of the cloud systems observed in the summer of 2018 and the sensitivity of the cloud layers to different micro- and macro-scale parameters. We find that the model generally reproduces the observed thermodynamic structure well, with two near-neutrally stratified layers in the BL caused by a low cloud (located within the first few hundred meters) capped by a lower-altitude temperature inversion and an upper cloud layer (based around one kilometer or slightly higher) capped by the main temperature inversion of the BL. The simulated cloud structure is persistent unless there are low aerosol number concentrations ( ≤ 5 cm −3 ), which cause the upper cloud layer to dissipate, or high large-scale wind speeds ( ≥ 8.5 m s −1 ) , which erode the lower inversion and the related cloud layer. The changes in cloud structure alter both the short- and longwave cloud radiative effect at the surface. This results in changes in the net radiative effect of the modeled cloud system, which can impact the surface melting or freezing. The findings highlight the importance of better understanding and representing aerosol sources and sinks over the central Arctic Ocean. Furthermore, they underline the significance of meteorological parameters, such as the large-scale wind speed, for maintaining the two-layer boundary-layer cloud structure encountered in the lower ... |
format |
Article in Journal/Newspaper |
author |
I. Bulatovic J. Savre M. Tjernström C. Leck A. M. L. Ekman |
author_facet |
I. Bulatovic J. Savre M. Tjernström C. Leck A. M. L. Ekman |
author_sort |
I. Bulatovic |
title |
Large-eddy simulation of a two-layer boundary-layer cloud system from the Arctic Ocean 2018 expedition |
title_short |
Large-eddy simulation of a two-layer boundary-layer cloud system from the Arctic Ocean 2018 expedition |
title_full |
Large-eddy simulation of a two-layer boundary-layer cloud system from the Arctic Ocean 2018 expedition |
title_fullStr |
Large-eddy simulation of a two-layer boundary-layer cloud system from the Arctic Ocean 2018 expedition |
title_full_unstemmed |
Large-eddy simulation of a two-layer boundary-layer cloud system from the Arctic Ocean 2018 expedition |
title_sort |
large-eddy simulation of a two-layer boundary-layer cloud system from the arctic ocean 2018 expedition |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/acp-23-7033-2023 https://doaj.org/article/760fcde143bb4b24aa0761097a0a921e |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Ocean Climate change |
genre_facet |
Arctic Arctic Ocean Climate change |
op_source |
Atmospheric Chemistry and Physics, Vol 23, Pp 7033-7055 (2023) |
op_relation |
https://acp.copernicus.org/articles/23/7033/2023/acp-23-7033-2023.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-23-7033-2023 1680-7316 1680-7324 https://doaj.org/article/760fcde143bb4b24aa0761097a0a921e |
op_doi |
https://doi.org/10.5194/acp-23-7033-2023 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
23 |
container_issue |
12 |
container_start_page |
7033 |
op_container_end_page |
7055 |
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1772178946917400576 |