Increasing cloudiness in Arctic damps the increase in phytoplankton primary production due to sea ice receding
The Arctic Ocean and its marginal seas are among the marine regions most affected by climate change. Here we present the results of a diagnostic model used to assess the primary production (PP) trends over the 1998–2010 period at pan-Arctic, regional and local (i.e. 9.28 km resolution) scales. Photo...
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ftcopernicus:oai:publications.copernicus.org:bg17075 2023-05-15T14:33:07+02:00 Increasing cloudiness in Arctic damps the increase in phytoplankton primary production due to sea ice receding Bélanger, S. Babin, M. Tremblay, J.-É. 2018-09-27 application/pdf https://doi.org/10.5194/bg-10-4087-2013 https://www.biogeosciences.net/10/4087/2013/ eng eng doi:10.5194/bg-10-4087-2013 https://www.biogeosciences.net/10/4087/2013/ eISSN: 1726-4189 Text 2018 ftcopernicus https://doi.org/10.5194/bg-10-4087-2013 2019-12-24T09:55:18Z The Arctic Ocean and its marginal seas are among the marine regions most affected by climate change. Here we present the results of a diagnostic model used to assess the primary production (PP) trends over the 1998–2010 period at pan-Arctic, regional and local (i.e. 9.28 km resolution) scales. Photosynthetically active radiation (PAR) above and below the sea surface was estimated using precomputed look-up tables of spectral irradiance, taking as input satellite-derived cloud optical thickness and cloud fraction parameters from the International Satellite Cloud Climatology Project (ISCCP) and sea ice concentration from passive microwaves data. A spectrally resolved PP model, designed for optically complex waters, was then used to assess the PP trends at high spatial resolution. Results show that PP is rising at a rate of +2.8 TgC yr −1 (or +14% decade −1 ) in the circum-Arctic and +5.1 TgC yr −1 when sub-Arctic seas are considered. In contrast, incident PAR above the sea surface (PAR(0+)) has significantly decreased over the whole Arctic and sub-Arctic Seas, except over the perennially sea-ice covered waters of the Central Arctic Ocean. This fading of PAR(0+) (−8% decade −1 ) was caused by increasing cloudiness during summer. Meanwhile, PAR penetrating the ocean (PAR(0−)) increased only along the sea ice margin over the large Arctic continental shelf where sea ice concentration declined sharply since 1998. Overall, PAR(0−) slightly increased in the circum-Arctic (+3.4% decade −1 ), while it decreased when considering both Arctic and sub-Arctic Seas (−3% decade −1 ). We showed that rising phytoplankton biomass (i.e. chlorophyll a ) normalized by the diffuse attenuation of photosynthetically usable radiation (PUR), accounted for a larger proportion of the rise in PP than did the increase in light availability due to sea-ice loss in several sectors, and particularly in perennially and seasonally open waters. Against a general backdrop of rising productivity over Arctic shelves, significant negative PP trends and the timing of phytoplankton spring-summer bloom were observed in regions known for their great biological importance such as the coastal polynyas of northern Greenland. Text Arctic Arctic Ocean Climate change Greenland Phytoplankton Sea ice ice covered waters Copernicus Publications: E-Journals Arctic Arctic Ocean Greenland Biogeosciences 10 6 4087 4101 |
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Copernicus Publications: E-Journals |
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English |
description |
The Arctic Ocean and its marginal seas are among the marine regions most affected by climate change. Here we present the results of a diagnostic model used to assess the primary production (PP) trends over the 1998–2010 period at pan-Arctic, regional and local (i.e. 9.28 km resolution) scales. Photosynthetically active radiation (PAR) above and below the sea surface was estimated using precomputed look-up tables of spectral irradiance, taking as input satellite-derived cloud optical thickness and cloud fraction parameters from the International Satellite Cloud Climatology Project (ISCCP) and sea ice concentration from passive microwaves data. A spectrally resolved PP model, designed for optically complex waters, was then used to assess the PP trends at high spatial resolution. Results show that PP is rising at a rate of +2.8 TgC yr −1 (or +14% decade −1 ) in the circum-Arctic and +5.1 TgC yr −1 when sub-Arctic seas are considered. In contrast, incident PAR above the sea surface (PAR(0+)) has significantly decreased over the whole Arctic and sub-Arctic Seas, except over the perennially sea-ice covered waters of the Central Arctic Ocean. This fading of PAR(0+) (−8% decade −1 ) was caused by increasing cloudiness during summer. Meanwhile, PAR penetrating the ocean (PAR(0−)) increased only along the sea ice margin over the large Arctic continental shelf where sea ice concentration declined sharply since 1998. Overall, PAR(0−) slightly increased in the circum-Arctic (+3.4% decade −1 ), while it decreased when considering both Arctic and sub-Arctic Seas (−3% decade −1 ). We showed that rising phytoplankton biomass (i.e. chlorophyll a ) normalized by the diffuse attenuation of photosynthetically usable radiation (PUR), accounted for a larger proportion of the rise in PP than did the increase in light availability due to sea-ice loss in several sectors, and particularly in perennially and seasonally open waters. Against a general backdrop of rising productivity over Arctic shelves, significant negative PP trends and the timing of phytoplankton spring-summer bloom were observed in regions known for their great biological importance such as the coastal polynyas of northern Greenland. |
format |
Text |
author |
Bélanger, S. Babin, M. Tremblay, J.-É. |
spellingShingle |
Bélanger, S. Babin, M. Tremblay, J.-É. Increasing cloudiness in Arctic damps the increase in phytoplankton primary production due to sea ice receding |
author_facet |
Bélanger, S. Babin, M. Tremblay, J.-É. |
author_sort |
Bélanger, S. |
title |
Increasing cloudiness in Arctic damps the increase in phytoplankton primary production due to sea ice receding |
title_short |
Increasing cloudiness in Arctic damps the increase in phytoplankton primary production due to sea ice receding |
title_full |
Increasing cloudiness in Arctic damps the increase in phytoplankton primary production due to sea ice receding |
title_fullStr |
Increasing cloudiness in Arctic damps the increase in phytoplankton primary production due to sea ice receding |
title_full_unstemmed |
Increasing cloudiness in Arctic damps the increase in phytoplankton primary production due to sea ice receding |
title_sort |
increasing cloudiness in arctic damps the increase in phytoplankton primary production due to sea ice receding |
publishDate |
2018 |
url |
https://doi.org/10.5194/bg-10-4087-2013 https://www.biogeosciences.net/10/4087/2013/ |
geographic |
Arctic Arctic Ocean Greenland |
geographic_facet |
Arctic Arctic Ocean Greenland |
genre |
Arctic Arctic Ocean Climate change Greenland Phytoplankton Sea ice ice covered waters |
genre_facet |
Arctic Arctic Ocean Climate change Greenland Phytoplankton Sea ice ice covered waters |
op_source |
eISSN: 1726-4189 |
op_relation |
doi:10.5194/bg-10-4087-2013 https://www.biogeosciences.net/10/4087/2013/ |
op_doi |
https://doi.org/10.5194/bg-10-4087-2013 |
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Biogeosciences |
container_volume |
10 |
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6 |
container_start_page |
4087 |
op_container_end_page |
4101 |
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