The winter stratification phenomenon and its consequences in the Gulf of Finland, Baltic Sea
Stratification plays an essential role in the marine ecosystem, with a shallow mixed layer being one of the preconditions for enhanced primary production in the ocean. In the Baltic Sea, the general understanding is that the upper mixed layer (UML) is well below the euphotic zone in winter. In this...
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ftcopernicus:oai:publications.copernicus.org:os85331 2023-05-15T17:33:37+02:00 The winter stratification phenomenon and its consequences in the Gulf of Finland, Baltic Sea Liblik, Taavi Väli, Germo Lips, Inga Lilover, Madis-Jaak Kikas, Villu Laanemets, Jaan 2020-12-01 application/pdf https://doi.org/10.5194/os-16-1475-2020 https://os.copernicus.org/articles/16/1475/2020/ eng eng doi:10.5194/os-16-1475-2020 https://os.copernicus.org/articles/16/1475/2020/ eISSN: 1812-0792 Text 2020 ftcopernicus https://doi.org/10.5194/os-16-1475-2020 2020-12-07T17:22:17Z Stratification plays an essential role in the marine ecosystem, with a shallow mixed layer being one of the preconditions for enhanced primary production in the ocean. In the Baltic Sea, the general understanding is that the upper mixed layer (UML) is well below the euphotic zone in winter. In this study, we demonstrate that wintertime shallow stratification is common in the Gulf of Finland and it forms at a depth comparable to the euphotic zone in January–February. The onset of restratification is likely associated with the annual cycle of westerly winds, which ease off in late January–early February. Stratification is first invoked along the northern coast by the westward advection of riverine water forced by easterly winds and is expanded to the south when the prevailing wind direction changes from an easterly to a westerly direction. Haline stratification emerges approximately 1 month later in the southern part of the gulf. Winter restratification can occur in the entire gulf and also in the absence of ice; thus, it is a regular seasonal feature in the area. Interannual variations in the wintertime UML correspond with variations in the North Atlantic Oscillation. Chlorophyll a concentrations in winter can be comparable to mid-summer; the limiting factor for phytoplankton bloom in winter is likely insufficient solar radiation. Text North Atlantic North Atlantic oscillation Copernicus Publications: E-Journals Ocean Science 16 6 1475 1490 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
Stratification plays an essential role in the marine ecosystem, with a shallow mixed layer being one of the preconditions for enhanced primary production in the ocean. In the Baltic Sea, the general understanding is that the upper mixed layer (UML) is well below the euphotic zone in winter. In this study, we demonstrate that wintertime shallow stratification is common in the Gulf of Finland and it forms at a depth comparable to the euphotic zone in January–February. The onset of restratification is likely associated with the annual cycle of westerly winds, which ease off in late January–early February. Stratification is first invoked along the northern coast by the westward advection of riverine water forced by easterly winds and is expanded to the south when the prevailing wind direction changes from an easterly to a westerly direction. Haline stratification emerges approximately 1 month later in the southern part of the gulf. Winter restratification can occur in the entire gulf and also in the absence of ice; thus, it is a regular seasonal feature in the area. Interannual variations in the wintertime UML correspond with variations in the North Atlantic Oscillation. Chlorophyll a concentrations in winter can be comparable to mid-summer; the limiting factor for phytoplankton bloom in winter is likely insufficient solar radiation. |
format |
Text |
author |
Liblik, Taavi Väli, Germo Lips, Inga Lilover, Madis-Jaak Kikas, Villu Laanemets, Jaan |
spellingShingle |
Liblik, Taavi Väli, Germo Lips, Inga Lilover, Madis-Jaak Kikas, Villu Laanemets, Jaan The winter stratification phenomenon and its consequences in the Gulf of Finland, Baltic Sea |
author_facet |
Liblik, Taavi Väli, Germo Lips, Inga Lilover, Madis-Jaak Kikas, Villu Laanemets, Jaan |
author_sort |
Liblik, Taavi |
title |
The winter stratification phenomenon and its consequences in the Gulf of Finland, Baltic Sea |
title_short |
The winter stratification phenomenon and its consequences in the Gulf of Finland, Baltic Sea |
title_full |
The winter stratification phenomenon and its consequences in the Gulf of Finland, Baltic Sea |
title_fullStr |
The winter stratification phenomenon and its consequences in the Gulf of Finland, Baltic Sea |
title_full_unstemmed |
The winter stratification phenomenon and its consequences in the Gulf of Finland, Baltic Sea |
title_sort |
winter stratification phenomenon and its consequences in the gulf of finland, baltic sea |
publishDate |
2020 |
url |
https://doi.org/10.5194/os-16-1475-2020 https://os.copernicus.org/articles/16/1475/2020/ |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_source |
eISSN: 1812-0792 |
op_relation |
doi:10.5194/os-16-1475-2020 https://os.copernicus.org/articles/16/1475/2020/ |
op_doi |
https://doi.org/10.5194/os-16-1475-2020 |
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Ocean Science |
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16 |
container_issue |
6 |
container_start_page |
1475 |
op_container_end_page |
1490 |
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1766132181702279168 |