On the relationship between mesoscale cellular convection and meteorological forcing: comparing the Southern Ocean against the North Pacific
Abstract. Marine atmospheric boundary layer (MABL) clouds cover vast areas over the ocean and have important radiative effects on the Earth's climate system. These radiative effects are known to be sensitive to the local organization, or structure, of the mesoscale cellular convection (MCC). A...
Published in: | Atmospheric Chemistry and Physics |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus GmbH
2023
|
Subjects: | |
Online Access: | http://hdl.handle.net/11343/344139 |
id |
ftumelbourne:oai:jupiter.its.unimelb.edu.au:11343/344139 |
---|---|
record_format |
openpolar |
spelling |
ftumelbourne:oai:jupiter.its.unimelb.edu.au:11343/344139 2024-06-02T08:14:46+00:00 On the relationship between mesoscale cellular convection and meteorological forcing: comparing the Southern Ocean against the North Pacific Lang, F Siems, ST Huang, Y Alinejadtabrizi, T Ackermann, L 2023-12-20 http://hdl.handle.net/11343/344139 en eng Copernicus GmbH issn:1680-7316 doi:10.5194/acp-24-1451-2024 Lang, F., Siems, S. T., Huang, Y., Alinejadtabrizi, T. & Ackermann, L. (2023). On the relationship between mesoscale cellular convection and meteorological forcing: comparing the Southern Ocean against the North Pacific. Atmospheric Chemistry and Physics, 24 (2), pp.1451-1466. https://doi.org/10.5194/acp-24-1451-2024. 1680-7324 http://hdl.handle.net/11343/344139 CC BY-NC https://creativecommons.org/licenses/by-nc/4.0 Journal Article 2023 ftumelbourne https://doi.org/10.5194/acp-24-1451-2024 2024-05-06T13:25:45Z Abstract. Marine atmospheric boundary layer (MABL) clouds cover vast areas over the ocean and have important radiative effects on the Earth's climate system. These radiative effects are known to be sensitive to the local organization, or structure, of the mesoscale cellular convection (MCC). A convolutional neural network model is used to identify the two idealized classes of MCC clouds, namely open and closed, over the Southern Ocean (SO) and Northwest Pacific (NP) from high-frequency geostationary Himawari-8 satellite observations. The results of the climatology show that MCC clouds are evenly distributed over the mid-latitude storm tracks for both hemispheres, with peaks poleward of the 40∘ latitude. Open-MCC clouds are more prevalent than closed MCC in both regions. An examination of the presumed meteorological forcing associated with open- and closed-MCC clouds is conducted to illustrate the influence of large-scale meteorological conditions. We establish the importance of the Kuroshio western boundary current in the spatial coverage of open and closed MCC across the NP, presumably through the supply of strong heat and moisture fluxes during marine cold-air outbreaks events. In regions where static stability is higher, we observe a more frequent occurrence of closed MCCs. This behavior contrasts markedly with that of open MCCs, whose formation and persistence are significantly influenced by the difference in temperature between the air and the sea surface. The occurrence frequency of closed MCC over the SO exhibits a significant diurnal cycle, while the diurnal cycle of closed MCC over the NP is less noticeable. Article in Journal/Newspaper Southern Ocean The University of Melbourne: Digital Repository Pacific Southern Ocean Atmospheric Chemistry and Physics 24 2 1451 1466 |
institution |
Open Polar |
collection |
The University of Melbourne: Digital Repository |
op_collection_id |
ftumelbourne |
language |
English |
description |
Abstract. Marine atmospheric boundary layer (MABL) clouds cover vast areas over the ocean and have important radiative effects on the Earth's climate system. These radiative effects are known to be sensitive to the local organization, or structure, of the mesoscale cellular convection (MCC). A convolutional neural network model is used to identify the two idealized classes of MCC clouds, namely open and closed, over the Southern Ocean (SO) and Northwest Pacific (NP) from high-frequency geostationary Himawari-8 satellite observations. The results of the climatology show that MCC clouds are evenly distributed over the mid-latitude storm tracks for both hemispheres, with peaks poleward of the 40∘ latitude. Open-MCC clouds are more prevalent than closed MCC in both regions. An examination of the presumed meteorological forcing associated with open- and closed-MCC clouds is conducted to illustrate the influence of large-scale meteorological conditions. We establish the importance of the Kuroshio western boundary current in the spatial coverage of open and closed MCC across the NP, presumably through the supply of strong heat and moisture fluxes during marine cold-air outbreaks events. In regions where static stability is higher, we observe a more frequent occurrence of closed MCCs. This behavior contrasts markedly with that of open MCCs, whose formation and persistence are significantly influenced by the difference in temperature between the air and the sea surface. The occurrence frequency of closed MCC over the SO exhibits a significant diurnal cycle, while the diurnal cycle of closed MCC over the NP is less noticeable. |
format |
Article in Journal/Newspaper |
author |
Lang, F Siems, ST Huang, Y Alinejadtabrizi, T Ackermann, L |
spellingShingle |
Lang, F Siems, ST Huang, Y Alinejadtabrizi, T Ackermann, L On the relationship between mesoscale cellular convection and meteorological forcing: comparing the Southern Ocean against the North Pacific |
author_facet |
Lang, F Siems, ST Huang, Y Alinejadtabrizi, T Ackermann, L |
author_sort |
Lang, F |
title |
On the relationship between mesoscale cellular convection and meteorological forcing: comparing the Southern Ocean against the North Pacific |
title_short |
On the relationship between mesoscale cellular convection and meteorological forcing: comparing the Southern Ocean against the North Pacific |
title_full |
On the relationship between mesoscale cellular convection and meteorological forcing: comparing the Southern Ocean against the North Pacific |
title_fullStr |
On the relationship between mesoscale cellular convection and meteorological forcing: comparing the Southern Ocean against the North Pacific |
title_full_unstemmed |
On the relationship between mesoscale cellular convection and meteorological forcing: comparing the Southern Ocean against the North Pacific |
title_sort |
on the relationship between mesoscale cellular convection and meteorological forcing: comparing the southern ocean against the north pacific |
publisher |
Copernicus GmbH |
publishDate |
2023 |
url |
http://hdl.handle.net/11343/344139 |
geographic |
Pacific Southern Ocean |
geographic_facet |
Pacific Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
issn:1680-7316 doi:10.5194/acp-24-1451-2024 Lang, F., Siems, S. T., Huang, Y., Alinejadtabrizi, T. & Ackermann, L. (2023). On the relationship between mesoscale cellular convection and meteorological forcing: comparing the Southern Ocean against the North Pacific. Atmospheric Chemistry and Physics, 24 (2), pp.1451-1466. https://doi.org/10.5194/acp-24-1451-2024. 1680-7324 http://hdl.handle.net/11343/344139 |
op_rights |
CC BY-NC https://creativecommons.org/licenses/by-nc/4.0 |
op_doi |
https://doi.org/10.5194/acp-24-1451-2024 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
24 |
container_issue |
2 |
container_start_page |
1451 |
op_container_end_page |
1466 |
_version_ |
1800738744275304448 |