South Atlantic response to El Niño–Southern Oscillation induced climate variability in an ocean general circulation model
[1] The response of the South Atlantic Ocean to El Niño-Southern Oscillation (ENSO) is investigated by means of an ocean general circulation model (ORCA2) forced with National Centers for Environmental Prediction (NCEP) reanalyses for the 1948–1999 period. Seasonal ENSO composites suggest that the E...
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ftunivcapetownir:oai:localhost:11427/16414 2023-05-15T18:21:07+02:00 South Atlantic response to El Niño–Southern Oscillation induced climate variability in an ocean general circulation model Colberg, F Reason, C J C Rodgers, K 2004-12-14 application/pdf http://hdl.handle.net/11427/16414 https://open.uct.ac.za/bitstream/11427/16414/1/Colberg_South_Atlantic_response_to_2004.pdf eng eng American Geophysical Union University of Cape Town Faculty of Science Department of Oceanography http://hdl.handle.net/11427/16414 https://open.uct.ac.za/bitstream/11427/16414/1/Colberg_South_Atlantic_response_to_2004.pdf Journal of Geophysical Research: Oceans http://onlinelibrary.wiley.com/doi/10.1029/2004JC002301/full ENSO modeling South Atlantic variability Journal Article 2004 ftunivcapetownir https://doi.org/10.1029/2004JC002301/full 2022-09-13T05:58:44Z [1] The response of the South Atlantic Ocean to El Niño-Southern Oscillation (ENSO) is investigated by means of an ocean general circulation model (ORCA2) forced with National Centers for Environmental Prediction (NCEP) reanalyses for the 1948–1999 period. Seasonal ENSO composites suggest that the ENSO-induced wind anomalies play a major role in driving upper ocean temperatures by altering the net surface heat fluxes, the meridional Ekman heat transport, and Ekman pumping. Model diagnostics indicate that the Ekman heat transport changes are in better agreement with the upper ocean temperature anomalies during the first half of the ENSO event whereas, in the latter half, the surface heat flux anomalies agree better. In general, the atmospheric forcing tends to lead to a coherent ocean response with a time lag of about one season. Subsurface temperatures evolve more slowly in response to ENSO forcing than the upper ocean. They receive time-filtered ENSO signals from mainly Ekman pumping (suction) and variations in thermocline depth that result in the poleward and equatorward margins of the subtropical gyre exhibiting temperature anomalies of the same sign but opposite to those in the central regions of the gyre. Article in Journal/Newspaper South Atlantic Ocean University of Cape Town: OpenUCT |
institution |
Open Polar |
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University of Cape Town: OpenUCT |
op_collection_id |
ftunivcapetownir |
language |
English |
topic |
ENSO modeling South Atlantic variability |
spellingShingle |
ENSO modeling South Atlantic variability Colberg, F Reason, C J C Rodgers, K South Atlantic response to El Niño–Southern Oscillation induced climate variability in an ocean general circulation model |
topic_facet |
ENSO modeling South Atlantic variability |
description |
[1] The response of the South Atlantic Ocean to El Niño-Southern Oscillation (ENSO) is investigated by means of an ocean general circulation model (ORCA2) forced with National Centers for Environmental Prediction (NCEP) reanalyses for the 1948–1999 period. Seasonal ENSO composites suggest that the ENSO-induced wind anomalies play a major role in driving upper ocean temperatures by altering the net surface heat fluxes, the meridional Ekman heat transport, and Ekman pumping. Model diagnostics indicate that the Ekman heat transport changes are in better agreement with the upper ocean temperature anomalies during the first half of the ENSO event whereas, in the latter half, the surface heat flux anomalies agree better. In general, the atmospheric forcing tends to lead to a coherent ocean response with a time lag of about one season. Subsurface temperatures evolve more slowly in response to ENSO forcing than the upper ocean. They receive time-filtered ENSO signals from mainly Ekman pumping (suction) and variations in thermocline depth that result in the poleward and equatorward margins of the subtropical gyre exhibiting temperature anomalies of the same sign but opposite to those in the central regions of the gyre. |
format |
Article in Journal/Newspaper |
author |
Colberg, F Reason, C J C Rodgers, K |
author_facet |
Colberg, F Reason, C J C Rodgers, K |
author_sort |
Colberg, F |
title |
South Atlantic response to El Niño–Southern Oscillation induced climate variability in an ocean general circulation model |
title_short |
South Atlantic response to El Niño–Southern Oscillation induced climate variability in an ocean general circulation model |
title_full |
South Atlantic response to El Niño–Southern Oscillation induced climate variability in an ocean general circulation model |
title_fullStr |
South Atlantic response to El Niño–Southern Oscillation induced climate variability in an ocean general circulation model |
title_full_unstemmed |
South Atlantic response to El Niño–Southern Oscillation induced climate variability in an ocean general circulation model |
title_sort |
south atlantic response to el niño–southern oscillation induced climate variability in an ocean general circulation model |
publisher |
American Geophysical Union |
publishDate |
2004 |
url |
http://hdl.handle.net/11427/16414 https://open.uct.ac.za/bitstream/11427/16414/1/Colberg_South_Atlantic_response_to_2004.pdf |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_source |
Journal of Geophysical Research: Oceans http://onlinelibrary.wiley.com/doi/10.1029/2004JC002301/full |
op_relation |
http://hdl.handle.net/11427/16414 https://open.uct.ac.za/bitstream/11427/16414/1/Colberg_South_Atlantic_response_to_2004.pdf |
op_doi |
https://doi.org/10.1029/2004JC002301/full |
_version_ |
1766200221431234560 |