SST subseasonal variability in the central Benguela upwelling system as inferred from satellite observations (1999-2009)
Subseasonal variability of Sea Surface Temperature (SST) in the central Benguela upwelling system is investigated using TMI satellite-derived data over the period 1999-2009. Spatial patterns and time-frequency characteristics of subseasonal variability are documented based on Empirical Orthogonal Fu...
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ftarchimer:oai:archimer.ifremer.fr:27565 2023-05-15T13:50:49+02:00 SST subseasonal variability in the central Benguela upwelling system as inferred from satellite observations (1999-2009) Goubanova, Katerina Illig, Serena Machu, Eric Garcon, Veronique Dewitte, Boris 2013-09 application/pdf https://archimer.ifremer.fr/doc/00164/27565/25928.pdf https://doi.org/10.1002/jgrc.20287 https://archimer.ifremer.fr/doc/00164/27565/ eng eng Amer Geophysical Union https://archimer.ifremer.fr/doc/00164/27565/25928.pdf doi:10.1002/jgrc.20287 https://archimer.ifremer.fr/doc/00164/27565/ 2013. American Geophysical Union. All Rights Reserved info:eu-repo/semantics/openAccess restricted use Journal Of Geophysical Research-oceans (0148-0027) (Amer Geophysical Union), 2013-09 , Vol. 118 , N. 9 , P. 4092-4110 Benguela upwelling satellite observations intraseasonal variability wind-SST relationship mean vertical stratification Antarctic oscillation text Publication info:eu-repo/semantics/article 2013 ftarchimer https://doi.org/10.1002/jgrc.20287 2021-09-23T20:23:40Z Subseasonal variability of Sea Surface Temperature (SST) in the central Benguela upwelling system is investigated using TMI satellite-derived data over the period 1999-2009. Spatial patterns and time-frequency characteristics of subseasonal variability are documented based on Empirical Orthogonal Functions (EOF) decomposition and wavelet analysis. Despite the land contamination of the TMI satellite data within approximately 100 km off the coast the first EOF of SST anomalies allows characterizing the coastal upwelling variability at the subseasonal scale. Two regimes of variability are evidenced: a submonthly (2-30 days) regime with a dominant 11 days oscillation and a lower frequency intraseasonal (30-90 days) regime with a dominant 61 days oscillation. Both regimes are modulated, to a large extent, by the local surface wind stress and are consistent with Ekman dynamics. The seasonality of the relationship between wind stress and SST for submonthly (intraseasonal) regime is characterized by a marked semiannual (annual) cycle, which is explained in terms of the impact of seasonal change of the upper ocean stratification on the vertical advection process. The wind-driven SST subseasonal variability is shown to be associated with eastward propagating disturbances in the midlatitudes corresponding to a wave number 4. The results also suggest an important role of the Antarctic Oscillation in modulating the intraseasonal wind-driven SST variability. The characteristics of the equatorial intraseasonal Kelvin waves are documented in order to discuss possible impact of remote oceanic forcing on SST variability along the coast in the Benguela upwelling system. Article in Journal/Newspaper Antarc* Antarctic Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Antarctic The Antarctic Journal of Geophysical Research: Oceans 118 9 4092 4110 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
topic |
Benguela upwelling satellite observations intraseasonal variability wind-SST relationship mean vertical stratification Antarctic oscillation |
spellingShingle |
Benguela upwelling satellite observations intraseasonal variability wind-SST relationship mean vertical stratification Antarctic oscillation Goubanova, Katerina Illig, Serena Machu, Eric Garcon, Veronique Dewitte, Boris SST subseasonal variability in the central Benguela upwelling system as inferred from satellite observations (1999-2009) |
topic_facet |
Benguela upwelling satellite observations intraseasonal variability wind-SST relationship mean vertical stratification Antarctic oscillation |
description |
Subseasonal variability of Sea Surface Temperature (SST) in the central Benguela upwelling system is investigated using TMI satellite-derived data over the period 1999-2009. Spatial patterns and time-frequency characteristics of subseasonal variability are documented based on Empirical Orthogonal Functions (EOF) decomposition and wavelet analysis. Despite the land contamination of the TMI satellite data within approximately 100 km off the coast the first EOF of SST anomalies allows characterizing the coastal upwelling variability at the subseasonal scale. Two regimes of variability are evidenced: a submonthly (2-30 days) regime with a dominant 11 days oscillation and a lower frequency intraseasonal (30-90 days) regime with a dominant 61 days oscillation. Both regimes are modulated, to a large extent, by the local surface wind stress and are consistent with Ekman dynamics. The seasonality of the relationship between wind stress and SST for submonthly (intraseasonal) regime is characterized by a marked semiannual (annual) cycle, which is explained in terms of the impact of seasonal change of the upper ocean stratification on the vertical advection process. The wind-driven SST subseasonal variability is shown to be associated with eastward propagating disturbances in the midlatitudes corresponding to a wave number 4. The results also suggest an important role of the Antarctic Oscillation in modulating the intraseasonal wind-driven SST variability. The characteristics of the equatorial intraseasonal Kelvin waves are documented in order to discuss possible impact of remote oceanic forcing on SST variability along the coast in the Benguela upwelling system. |
format |
Article in Journal/Newspaper |
author |
Goubanova, Katerina Illig, Serena Machu, Eric Garcon, Veronique Dewitte, Boris |
author_facet |
Goubanova, Katerina Illig, Serena Machu, Eric Garcon, Veronique Dewitte, Boris |
author_sort |
Goubanova, Katerina |
title |
SST subseasonal variability in the central Benguela upwelling system as inferred from satellite observations (1999-2009) |
title_short |
SST subseasonal variability in the central Benguela upwelling system as inferred from satellite observations (1999-2009) |
title_full |
SST subseasonal variability in the central Benguela upwelling system as inferred from satellite observations (1999-2009) |
title_fullStr |
SST subseasonal variability in the central Benguela upwelling system as inferred from satellite observations (1999-2009) |
title_full_unstemmed |
SST subseasonal variability in the central Benguela upwelling system as inferred from satellite observations (1999-2009) |
title_sort |
sst subseasonal variability in the central benguela upwelling system as inferred from satellite observations (1999-2009) |
publisher |
Amer Geophysical Union |
publishDate |
2013 |
url |
https://archimer.ifremer.fr/doc/00164/27565/25928.pdf https://doi.org/10.1002/jgrc.20287 https://archimer.ifremer.fr/doc/00164/27565/ |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Journal Of Geophysical Research-oceans (0148-0027) (Amer Geophysical Union), 2013-09 , Vol. 118 , N. 9 , P. 4092-4110 |
op_relation |
https://archimer.ifremer.fr/doc/00164/27565/25928.pdf doi:10.1002/jgrc.20287 https://archimer.ifremer.fr/doc/00164/27565/ |
op_rights |
2013. American Geophysical Union. All Rights Reserved info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1002/jgrc.20287 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
118 |
container_issue |
9 |
container_start_page |
4092 |
op_container_end_page |
4110 |
_version_ |
1766254111712346112 |