Spatial and temporal variability of the remotely sensed chlorophyll a signal associated with Rossby waves in the South Atlantic Ocean
The present study focuses on the spatial and temporal variability of interactions between physics and biogeochemistry during the Rossby wave passage in the South Atlantic Ocean. The Rossby wave signature in sea level anomalies (SLA) and surface chlorophyll a concentration anomalies (CHLA) is analyze...
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ftarchimer:oai:archimer.ifremer.fr:13723 2023-05-15T18:20:43+02:00 Spatial and temporal variability of the remotely sensed chlorophyll a signal associated with Rossby waves in the South Atlantic Ocean Gutknecht, Elodie Dadou, Isabelle Charria, Guillaume Cipollini, Paolo Garcon, Veronique 2010-05-04 application/pdf https://archimer.ifremer.fr/doc/00026/13723/10832.pdf https://doi.org/10.1029/2009JC005291 https://archimer.ifremer.fr/doc/00026/13723/ eng eng American Geophysical Union https://archimer.ifremer.fr/doc/00026/13723/10832.pdf doi:10.1029/2009JC005291 https://archimer.ifremer.fr/doc/00026/13723/ 2010 American Geophysical Union info:eu-repo/semantics/openAccess restricted use Journal of Geophysical Research ( JGR ) - Oceans (0148-0227) (American Geophysical Union), 2010-05-04 , Vol. 115 , N. C05004 , P. 16 p. text Publication info:eu-repo/semantics/article 2010 ftarchimer https://doi.org/10.1029/2009JC005291 2021-09-23T20:19:06Z The present study focuses on the spatial and temporal variability of interactions between physics and biogeochemistry during the Rossby wave passage in the South Atlantic Ocean. The Rossby wave signature in sea level anomalies (SLA) and surface chlorophyll a concentration anomalies (CHLA) is analyzed using remotely sensed data from 1997 to 2006. Wavelengths between 400 and 1100 km, with westward propagating speeds up to 7.5 cm.s−1, are observed. Using a theoretical model, three processes (meridional advection of surface chlorophyll a concentrations, uplifting of subsurface chlorophyll a maximum, and upwelling of nutrients) are likely to explain the chlorophyll a Rossby wave signature. A statistical assumption allows quantifying the relative importance of each process. Three zones are identified. The Subtropical Gyre is the only area where the contribution of the uplifting process reaches 20%. North and south of this gyre, the meridional advection process is responsible for an important part (around 60%) of the observed chlorophyll a signals. The temporal variability of this dominant process is studied using the phase relationships between CHLA and SLA and the surface meridional chlorophyll a gradient. A seasonal meridional shift (4°) is shown on both data sets on the area of negative meridional gradient. At 30°S–31°S, a clear seasonal cycle is observed in both data sets for the whole studied period, except in 2003 and 2004 where both data sets do not follow the usual seasonal cycle. These particular years can be related to anomalies in large scale atmospheric circulation over the South Atlantic Ocean. Article in Journal/Newspaper South Atlantic Ocean Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Journal of Geophysical Research 115 C5 |
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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 |
description |
The present study focuses on the spatial and temporal variability of interactions between physics and biogeochemistry during the Rossby wave passage in the South Atlantic Ocean. The Rossby wave signature in sea level anomalies (SLA) and surface chlorophyll a concentration anomalies (CHLA) is analyzed using remotely sensed data from 1997 to 2006. Wavelengths between 400 and 1100 km, with westward propagating speeds up to 7.5 cm.s−1, are observed. Using a theoretical model, three processes (meridional advection of surface chlorophyll a concentrations, uplifting of subsurface chlorophyll a maximum, and upwelling of nutrients) are likely to explain the chlorophyll a Rossby wave signature. A statistical assumption allows quantifying the relative importance of each process. Three zones are identified. The Subtropical Gyre is the only area where the contribution of the uplifting process reaches 20%. North and south of this gyre, the meridional advection process is responsible for an important part (around 60%) of the observed chlorophyll a signals. The temporal variability of this dominant process is studied using the phase relationships between CHLA and SLA and the surface meridional chlorophyll a gradient. A seasonal meridional shift (4°) is shown on both data sets on the area of negative meridional gradient. At 30°S–31°S, a clear seasonal cycle is observed in both data sets for the whole studied period, except in 2003 and 2004 where both data sets do not follow the usual seasonal cycle. These particular years can be related to anomalies in large scale atmospheric circulation over the South Atlantic Ocean. |
format |
Article in Journal/Newspaper |
author |
Gutknecht, Elodie Dadou, Isabelle Charria, Guillaume Cipollini, Paolo Garcon, Veronique |
spellingShingle |
Gutknecht, Elodie Dadou, Isabelle Charria, Guillaume Cipollini, Paolo Garcon, Veronique Spatial and temporal variability of the remotely sensed chlorophyll a signal associated with Rossby waves in the South Atlantic Ocean |
author_facet |
Gutknecht, Elodie Dadou, Isabelle Charria, Guillaume Cipollini, Paolo Garcon, Veronique |
author_sort |
Gutknecht, Elodie |
title |
Spatial and temporal variability of the remotely sensed chlorophyll a signal associated with Rossby waves in the South Atlantic Ocean |
title_short |
Spatial and temporal variability of the remotely sensed chlorophyll a signal associated with Rossby waves in the South Atlantic Ocean |
title_full |
Spatial and temporal variability of the remotely sensed chlorophyll a signal associated with Rossby waves in the South Atlantic Ocean |
title_fullStr |
Spatial and temporal variability of the remotely sensed chlorophyll a signal associated with Rossby waves in the South Atlantic Ocean |
title_full_unstemmed |
Spatial and temporal variability of the remotely sensed chlorophyll a signal associated with Rossby waves in the South Atlantic Ocean |
title_sort |
spatial and temporal variability of the remotely sensed chlorophyll a signal associated with rossby waves in the south atlantic ocean |
publisher |
American Geophysical Union |
publishDate |
2010 |
url |
https://archimer.ifremer.fr/doc/00026/13723/10832.pdf https://doi.org/10.1029/2009JC005291 https://archimer.ifremer.fr/doc/00026/13723/ |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_source |
Journal of Geophysical Research ( JGR ) - Oceans (0148-0227) (American Geophysical Union), 2010-05-04 , Vol. 115 , N. C05004 , P. 16 p. |
op_relation |
https://archimer.ifremer.fr/doc/00026/13723/10832.pdf doi:10.1029/2009JC005291 https://archimer.ifremer.fr/doc/00026/13723/ |
op_rights |
2010 American Geophysical Union info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1029/2009JC005291 |
container_title |
Journal of Geophysical Research |
container_volume |
115 |
container_issue |
C5 |
_version_ |
1766198556458221568 |