Hydrographic controls on the inter-annual variability of chlorophyll-a concentration estimates in the Atlantic Sector of the Southern Ocean
Despite the high macro-nutrient content of waters transported by the Antarctic Circumpolar Current, most of the Southern Ocean waters fall in the High Nutrient Low Chlorophyll category. Exceptions are found downstream from islands or along coastal shelves, which are believed to be sources of the bio...
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ftawi:oai:epic.awi.de:25754 2023-05-15T13:46:51+02:00 Hydrographic controls on the inter-annual variability of chlorophyll-a concentration estimates in the Atlantic Sector of the Southern Ocean Borrione, Ines Schlitzer, Reiner 2011-06 application/pdf https://epic.awi.de/id/eprint/25754/ https://epic.awi.de/id/eprint/25754/1/WHOI_June2011-poster.pdf https://hdl.handle.net/10013/epic.39051 https://hdl.handle.net/10013/epic.39051.d001 unknown https://epic.awi.de/id/eprint/25754/1/WHOI_June2011-poster.pdf https://hdl.handle.net/10013/epic.39051.d001 Borrione, I. and Schlitzer, R. orcid:0000-0002-3740-6499 (2011) Hydrographic controls on the inter-annual variability of chlorophyll-a concentration estimates in the Atlantic Sector of the Southern Ocean , Modeling and Synthesis of Southern Ocean Natural Iron Fertilization Workshop, Woods Hole Oceanographic Institution, Woods Hole - U.S.A. . hdl:10013/epic.39051 EPIC3Modeling and Synthesis of Southern Ocean Natural Iron Fertilization Workshop, Woods Hole Oceanographic Institution, Woods Hole - U.S.A. Conference notRev 2011 ftawi 2021-12-24T15:35:30Z Despite the high macro-nutrient content of waters transported by the Antarctic Circumpolar Current, most of the Southern Ocean waters fall in the High Nutrient Low Chlorophyll category. Exceptions are found downstream from islands or along coastal shelves, which are believed to be sources of the bio-limiting nutrient iron. Nevertheless, further top-down and bottom-up controls may play an important role in affecting the recurrence and distribution of phytoplankton blooms. Analyzing a 13-year long time series of satellite ocean color imagery for the Atlantic sector of the Southern Ocean, we have detected two well confined regions, in the southern Drake Passage and downstream from South Georgia, where inter-annual variability is surprisingly low. We thus combined satellite based sea surface height data and diverse langrangian measurements of circulation (Argo floats and surface drifters) to investigate existing connections between local hydrography and the observed chl-a patterns. Our results highlight how the occurrence and distribution of the observed pigment biomass is strongly controlled by surface circulation, which not only is responsible for the dispersal of chlorophyll-a patches but also that of micro-nutrients, possibly including iron. Our observations lead us to the conclusion that the topographic steering of the currents may also determine the stability of the observed patterns. Furthermore, we observe how both in the Southern Drake Passage, and downstream from South Georgia, higher chlorophyll-a concentrations are measured where a meander is formed. Combining our observations with those derived from other natural iron enrichment studies in the Southern Ocean (i.e. in the Crozet and Kerguelen Islands), we argue that downstream from a nutrient source the presence of a meander with greater elocities, yet embracing calmer waters, may act as a preconditioner to the observed higher chlorophyll-a concentrations. Conference Object Antarc* Antarctic Drake Passage Kerguelen Islands Southern Ocean Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Antarctic Southern Ocean The Antarctic Kerguelen Drake Passage Kerguelen Islands |
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Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
Despite the high macro-nutrient content of waters transported by the Antarctic Circumpolar Current, most of the Southern Ocean waters fall in the High Nutrient Low Chlorophyll category. Exceptions are found downstream from islands or along coastal shelves, which are believed to be sources of the bio-limiting nutrient iron. Nevertheless, further top-down and bottom-up controls may play an important role in affecting the recurrence and distribution of phytoplankton blooms. Analyzing a 13-year long time series of satellite ocean color imagery for the Atlantic sector of the Southern Ocean, we have detected two well confined regions, in the southern Drake Passage and downstream from South Georgia, where inter-annual variability is surprisingly low. We thus combined satellite based sea surface height data and diverse langrangian measurements of circulation (Argo floats and surface drifters) to investigate existing connections between local hydrography and the observed chl-a patterns. Our results highlight how the occurrence and distribution of the observed pigment biomass is strongly controlled by surface circulation, which not only is responsible for the dispersal of chlorophyll-a patches but also that of micro-nutrients, possibly including iron. Our observations lead us to the conclusion that the topographic steering of the currents may also determine the stability of the observed patterns. Furthermore, we observe how both in the Southern Drake Passage, and downstream from South Georgia, higher chlorophyll-a concentrations are measured where a meander is formed. Combining our observations with those derived from other natural iron enrichment studies in the Southern Ocean (i.e. in the Crozet and Kerguelen Islands), we argue that downstream from a nutrient source the presence of a meander with greater elocities, yet embracing calmer waters, may act as a preconditioner to the observed higher chlorophyll-a concentrations. |
format |
Conference Object |
author |
Borrione, Ines Schlitzer, Reiner |
spellingShingle |
Borrione, Ines Schlitzer, Reiner Hydrographic controls on the inter-annual variability of chlorophyll-a concentration estimates in the Atlantic Sector of the Southern Ocean |
author_facet |
Borrione, Ines Schlitzer, Reiner |
author_sort |
Borrione, Ines |
title |
Hydrographic controls on the inter-annual variability of chlorophyll-a concentration estimates in the Atlantic Sector of the Southern Ocean |
title_short |
Hydrographic controls on the inter-annual variability of chlorophyll-a concentration estimates in the Atlantic Sector of the Southern Ocean |
title_full |
Hydrographic controls on the inter-annual variability of chlorophyll-a concentration estimates in the Atlantic Sector of the Southern Ocean |
title_fullStr |
Hydrographic controls on the inter-annual variability of chlorophyll-a concentration estimates in the Atlantic Sector of the Southern Ocean |
title_full_unstemmed |
Hydrographic controls on the inter-annual variability of chlorophyll-a concentration estimates in the Atlantic Sector of the Southern Ocean |
title_sort |
hydrographic controls on the inter-annual variability of chlorophyll-a concentration estimates in the atlantic sector of the southern ocean |
publishDate |
2011 |
url |
https://epic.awi.de/id/eprint/25754/ https://epic.awi.de/id/eprint/25754/1/WHOI_June2011-poster.pdf https://hdl.handle.net/10013/epic.39051 https://hdl.handle.net/10013/epic.39051.d001 |
geographic |
Antarctic Southern Ocean The Antarctic Kerguelen Drake Passage Kerguelen Islands |
geographic_facet |
Antarctic Southern Ocean The Antarctic Kerguelen Drake Passage Kerguelen Islands |
genre |
Antarc* Antarctic Drake Passage Kerguelen Islands Southern Ocean |
genre_facet |
Antarc* Antarctic Drake Passage Kerguelen Islands Southern Ocean |
op_source |
EPIC3Modeling and Synthesis of Southern Ocean Natural Iron Fertilization Workshop, Woods Hole Oceanographic Institution, Woods Hole - U.S.A. |
op_relation |
https://epic.awi.de/id/eprint/25754/1/WHOI_June2011-poster.pdf https://hdl.handle.net/10013/epic.39051.d001 Borrione, I. and Schlitzer, R. orcid:0000-0002-3740-6499 (2011) Hydrographic controls on the inter-annual variability of chlorophyll-a concentration estimates in the Atlantic Sector of the Southern Ocean , Modeling and Synthesis of Southern Ocean Natural Iron Fertilization Workshop, Woods Hole Oceanographic Institution, Woods Hole - U.S.A. . hdl:10013/epic.39051 |
_version_ |
1766245346455846912 |