Downstream development during ridging South Atlantic Ocean anticyclones
This work is part of a broader project that aims is to understand the underlying dynamical processes of the important synoptic systems in the South Atlantic Ocean/South Africa basin. AVAILABILITY OF DATA AND MATERIALS : This study has been supported by the Water Research Foundation (Grant number: C2...
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ftunivpretoria:oai:repository.up.ac.za:2263/95765 2024-05-19T07:48:30+00:00 Downstream development during ridging South Atlantic Ocean anticyclones Ndarana, Thando Lekoloane, Lesetja E. Rammopo, Tsholanang S. Reason, Chris J.C. Chikoore, Hector Engelbrecht, Francois A. 2023-09 application/pdf http://hdl.handle.net/2263/95765 https://doi.org/10.1007/s00382-023-06717-7 en eng Springer Ndarana, T., Lekoloane, L.E., Rammopo, T.S. et al. 2023, 'Downstream development during ridging South Atlantic Ocean anticyclones', Climate Dynamics, vol. 61, pp. 2865-2883. https://DOI.org/10.1007/s00382-023-06717-7. 0930-7575 (print) 1432-0894 (online) doi:10.1007/s00382-023-06717-7 http://hdl.handle.net/2263/95765 © The Author(s) 2023. This article is licensed under a Creative Commons Attribution 4.0 International License. Downstream development Ridging highs Jet streaks SDG-13: Climate Action Cut-off low (COL) Article 2023 ftunivpretoria https://doi.org/10.1007/s00382-023-06717-7 2024-04-30T23:36:20Z This work is part of a broader project that aims is to understand the underlying dynamical processes of the important synoptic systems in the South Atlantic Ocean/South Africa basin. AVAILABILITY OF DATA AND MATERIALS : This study has been supported by the Water Research Foundation (Grant number: C2020/2021-00653) of South Africa and it is part of a larger project that aims to understand the underlying dynamical processes of the important synoptic systems in the South Atlantic Ocean/South Africa basin. All the data used in the study was obtained are the Fifth Generation European Centre for Medium-Range Weather Forecasts reanalysis (ERA5) can be obtained from. https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era5 Ridging South Atlantic high pressure systems (ridging highs) are often accompanied by cut-off low (COL) pressure systems aloft, but may also occur without them, in which case a linear baroclinic wave would be observed propagating across the South African domain in the upper troposphere. Using 41 years of ERA-5 reanalysis data, this study documents differences between the characteristics of the prevailing dynamical processes and associated local eddy kinetic energy generation, its downstream transfer and dissipation during these two scenarios. The study shows that when COLs are present then baroclinic conversion is strong and it is confined east of the Greenwich Meridian, whereas it is located downstream of South Africa and it is much weaker, when ridging occurs without COLs. The differences in strength and locations of the baroclinic conversion are associated with the differing jet streak configurations between the two scenarios; which lead to Rossby wave breaking and the absence thereof when there are COLs and when ridging occurs without COLs, respectively. The presence of breaking during COLs leads to trans-ridge downstream development that facilitates energy transfer from the midlatitudes into the South African domain. When there are no COLs present, the trans-trough downstream ... Article in Journal/Newspaper South Atlantic Ocean University of Pretoria: UPSpace Climate Dynamics 61 5-6 2865 2883 |
institution |
Open Polar |
collection |
University of Pretoria: UPSpace |
op_collection_id |
ftunivpretoria |
language |
English |
topic |
Downstream development Ridging highs Jet streaks SDG-13: Climate Action Cut-off low (COL) |
spellingShingle |
Downstream development Ridging highs Jet streaks SDG-13: Climate Action Cut-off low (COL) Ndarana, Thando Lekoloane, Lesetja E. Rammopo, Tsholanang S. Reason, Chris J.C. Chikoore, Hector Engelbrecht, Francois A. Downstream development during ridging South Atlantic Ocean anticyclones |
topic_facet |
Downstream development Ridging highs Jet streaks SDG-13: Climate Action Cut-off low (COL) |
description |
This work is part of a broader project that aims is to understand the underlying dynamical processes of the important synoptic systems in the South Atlantic Ocean/South Africa basin. AVAILABILITY OF DATA AND MATERIALS : This study has been supported by the Water Research Foundation (Grant number: C2020/2021-00653) of South Africa and it is part of a larger project that aims to understand the underlying dynamical processes of the important synoptic systems in the South Atlantic Ocean/South Africa basin. All the data used in the study was obtained are the Fifth Generation European Centre for Medium-Range Weather Forecasts reanalysis (ERA5) can be obtained from. https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era5 Ridging South Atlantic high pressure systems (ridging highs) are often accompanied by cut-off low (COL) pressure systems aloft, but may also occur without them, in which case a linear baroclinic wave would be observed propagating across the South African domain in the upper troposphere. Using 41 years of ERA-5 reanalysis data, this study documents differences between the characteristics of the prevailing dynamical processes and associated local eddy kinetic energy generation, its downstream transfer and dissipation during these two scenarios. The study shows that when COLs are present then baroclinic conversion is strong and it is confined east of the Greenwich Meridian, whereas it is located downstream of South Africa and it is much weaker, when ridging occurs without COLs. The differences in strength and locations of the baroclinic conversion are associated with the differing jet streak configurations between the two scenarios; which lead to Rossby wave breaking and the absence thereof when there are COLs and when ridging occurs without COLs, respectively. The presence of breaking during COLs leads to trans-ridge downstream development that facilitates energy transfer from the midlatitudes into the South African domain. When there are no COLs present, the trans-trough downstream ... |
format |
Article in Journal/Newspaper |
author |
Ndarana, Thando Lekoloane, Lesetja E. Rammopo, Tsholanang S. Reason, Chris J.C. Chikoore, Hector Engelbrecht, Francois A. |
author_facet |
Ndarana, Thando Lekoloane, Lesetja E. Rammopo, Tsholanang S. Reason, Chris J.C. Chikoore, Hector Engelbrecht, Francois A. |
author_sort |
Ndarana, Thando |
title |
Downstream development during ridging South Atlantic Ocean anticyclones |
title_short |
Downstream development during ridging South Atlantic Ocean anticyclones |
title_full |
Downstream development during ridging South Atlantic Ocean anticyclones |
title_fullStr |
Downstream development during ridging South Atlantic Ocean anticyclones |
title_full_unstemmed |
Downstream development during ridging South Atlantic Ocean anticyclones |
title_sort |
downstream development during ridging south atlantic ocean anticyclones |
publisher |
Springer |
publishDate |
2023 |
url |
http://hdl.handle.net/2263/95765 https://doi.org/10.1007/s00382-023-06717-7 |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_relation |
Ndarana, T., Lekoloane, L.E., Rammopo, T.S. et al. 2023, 'Downstream development during ridging South Atlantic Ocean anticyclones', Climate Dynamics, vol. 61, pp. 2865-2883. https://DOI.org/10.1007/s00382-023-06717-7. 0930-7575 (print) 1432-0894 (online) doi:10.1007/s00382-023-06717-7 http://hdl.handle.net/2263/95765 |
op_rights |
© The Author(s) 2023. This article is licensed under a Creative Commons Attribution 4.0 International License. |
op_doi |
https://doi.org/10.1007/s00382-023-06717-7 |
container_title |
Climate Dynamics |
container_volume |
61 |
container_issue |
5-6 |
container_start_page |
2865 |
op_container_end_page |
2883 |
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1799466777049038848 |