Annual nitrate drawdown observed by SOCCOM profiling floats and the relationship to annual net community production
Annual nitrate cycles have been measured throughout the pelagic waters of the Southern Ocean, including regions with seasonal ice cover and southern hemisphere subtropical zones. Vertically resolved nitrate measurements were made using in situ ultraviolet spectrophotometer (ISUS) and submersible ult...
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fttriple:oai:gotriple.eu:10670/1.0nob6z 2023-05-15T18:24:34+02:00 Annual nitrate drawdown observed by SOCCOM profiling floats and the relationship to annual net community production Johnson, Kenneth S. Plant, Joshua N. Dunne, John P. Talley, Lynne D. Sarmiento, Jorge L. https://doi.org/10.1002/2017JC012839 https://archimer.ifremer.fr/doc/00662/77397/78994.pdf https://archimer.ifremer.fr/doc/00662/77397/ en eng Amer Geophysical Union doi:10.1002/2017JC012839 10670/1.0nob6z https://archimer.ifremer.fr/doc/00662/77397/78994.pdf https://archimer.ifremer.fr/doc/00662/77397/ other Archimer, archive institutionnelle de l'Ifremer Journal Of Geophysical Research-oceans (2169-9275) (Amer Geophysical Union), 2017-08 , Vol. 122 , N. 8 , P. 6668-6683 envir geo Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ fttriple https://doi.org/10.1002/2017JC012839 2023-01-22T17:32:03Z Annual nitrate cycles have been measured throughout the pelagic waters of the Southern Ocean, including regions with seasonal ice cover and southern hemisphere subtropical zones. Vertically resolved nitrate measurements were made using in situ ultraviolet spectrophotometer (ISUS) and submersible ultraviolet nitrate analyzer (SUNA) optical nitrate sensors deployed on profiling floats. Thirty-one floats returned 40 complete annual cycles. The mean nitrate profile from the month with the highest winter nitrate minus the mean profile from the month with the lowest nitrate yields the annual nitrate drawdown. This quantity was integrated to 200 m depth and converted to carbon using the Redfield ratio to estimate annual net community production (ANCP) throughout the Southern Ocean south of 30 degrees S. A well-defined, zonal mean distribution is found with highest values (3-4 mol C m(-2) yr(-1)) from 40 to 50 degrees S. Lowest values are found in the subtropics and in the seasonal ice zone. The area weighted mean was 2.9 mol C m(-2) yr(-1) for all regions south of 40 degrees S. Cumulative ANCP south of 50 degrees S is 1.3 Pg C yr(-1). This represents about 13% of global ANCP in about 14% of the global ocean area. Plain Language Summary This manuscript reports on 40 annual cycles of nitrate observed by chemical sensors on SOCCOM profiling floats. The annual drawdown in nitrate concentration by phytoplankton is used to assess the spatial variability of annual net community production in the Southern Ocean. This ANCP is a key component of the global carbon cycle and it exerts an important control on atmospheric carbon dioxide. We show that the results are consistent with our prior understanding of Southern Ocean ANCP, which has required decades of observations to accumulate. The profiling floats now enable annual resolution of this key process. The results also highlight spatial variability in ANCP in the Southern Ocean. Text Southern Ocean Unknown Southern Ocean Journal of Geophysical Research: Oceans 122 8 6668 6683 |
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envir geo Johnson, Kenneth S. Plant, Joshua N. Dunne, John P. Talley, Lynne D. Sarmiento, Jorge L. Annual nitrate drawdown observed by SOCCOM profiling floats and the relationship to annual net community production |
topic_facet |
envir geo |
description |
Annual nitrate cycles have been measured throughout the pelagic waters of the Southern Ocean, including regions with seasonal ice cover and southern hemisphere subtropical zones. Vertically resolved nitrate measurements were made using in situ ultraviolet spectrophotometer (ISUS) and submersible ultraviolet nitrate analyzer (SUNA) optical nitrate sensors deployed on profiling floats. Thirty-one floats returned 40 complete annual cycles. The mean nitrate profile from the month with the highest winter nitrate minus the mean profile from the month with the lowest nitrate yields the annual nitrate drawdown. This quantity was integrated to 200 m depth and converted to carbon using the Redfield ratio to estimate annual net community production (ANCP) throughout the Southern Ocean south of 30 degrees S. A well-defined, zonal mean distribution is found with highest values (3-4 mol C m(-2) yr(-1)) from 40 to 50 degrees S. Lowest values are found in the subtropics and in the seasonal ice zone. The area weighted mean was 2.9 mol C m(-2) yr(-1) for all regions south of 40 degrees S. Cumulative ANCP south of 50 degrees S is 1.3 Pg C yr(-1). This represents about 13% of global ANCP in about 14% of the global ocean area. Plain Language Summary This manuscript reports on 40 annual cycles of nitrate observed by chemical sensors on SOCCOM profiling floats. The annual drawdown in nitrate concentration by phytoplankton is used to assess the spatial variability of annual net community production in the Southern Ocean. This ANCP is a key component of the global carbon cycle and it exerts an important control on atmospheric carbon dioxide. We show that the results are consistent with our prior understanding of Southern Ocean ANCP, which has required decades of observations to accumulate. The profiling floats now enable annual resolution of this key process. The results also highlight spatial variability in ANCP in the Southern Ocean. |
format |
Text |
author |
Johnson, Kenneth S. Plant, Joshua N. Dunne, John P. Talley, Lynne D. Sarmiento, Jorge L. |
author_facet |
Johnson, Kenneth S. Plant, Joshua N. Dunne, John P. Talley, Lynne D. Sarmiento, Jorge L. |
author_sort |
Johnson, Kenneth S. |
title |
Annual nitrate drawdown observed by SOCCOM profiling floats and the relationship to annual net community production |
title_short |
Annual nitrate drawdown observed by SOCCOM profiling floats and the relationship to annual net community production |
title_full |
Annual nitrate drawdown observed by SOCCOM profiling floats and the relationship to annual net community production |
title_fullStr |
Annual nitrate drawdown observed by SOCCOM profiling floats and the relationship to annual net community production |
title_full_unstemmed |
Annual nitrate drawdown observed by SOCCOM profiling floats and the relationship to annual net community production |
title_sort |
annual nitrate drawdown observed by soccom profiling floats and the relationship to annual net community production |
publisher |
Amer Geophysical Union |
url |
https://doi.org/10.1002/2017JC012839 https://archimer.ifremer.fr/doc/00662/77397/78994.pdf https://archimer.ifremer.fr/doc/00662/77397/ |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Archimer, archive institutionnelle de l'Ifremer Journal Of Geophysical Research-oceans (2169-9275) (Amer Geophysical Union), 2017-08 , Vol. 122 , N. 8 , P. 6668-6683 |
op_relation |
doi:10.1002/2017JC012839 10670/1.0nob6z https://archimer.ifremer.fr/doc/00662/77397/78994.pdf https://archimer.ifremer.fr/doc/00662/77397/ |
op_rights |
other |
op_doi |
https://doi.org/10.1002/2017JC012839 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
122 |
container_issue |
8 |
container_start_page |
6668 |
op_container_end_page |
6683 |
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1766205255755759616 |