Ashley Arroyo, Mary-Louise Timmermans, Mike DeGrandpre
{"title":"量化加拿大盆地混合层溶解氧季节和年际变化的驱动因素","authors":"Ashley Arroyo, Mary-Louise Timmermans, Mike DeGrandpre","doi":"10.1029/2024JC020903","DOIUrl":null,"url":null,"abstract":"<p>Analysis of dissolved oxygen (O<sub>2</sub>) in the Arctic's surface ocean provides insights into gas transfer between the atmosphere-ice-ocean system, water mass dynamics, and biogeochemical processes. In the Arctic Ocean's Canada Basin mixed layer, higher O<sub>2</sub> concentrations are generally observed under sea ice compared to open water regions. Annual cycles of O<sub>2</sub> and O<sub>2</sub> saturation, increasing from summer through spring and then sharply declining to late summer, are tightly linked to sea ice cover. The primary fluxes that influence seasonal variability of O<sub>2</sub> are modeled and compared to Ice-Tethered Profiler O<sub>2</sub> observations to understand the relative role of each flux in the annual cycle. Findings suggest that sea ice melt/growth dominates seasonal variations in mixed layer O<sub>2</sub>, with minor contributions from vertical entrainment and atmospheric exchange. While the influence of biological activity on O<sub>2</sub> variability cannot be directly assessed, indirect evidence suggests relatively minor contributions, although with significant uncertainty. Past studies show that O<sub>2</sub> molecules are expelled from sea ice during brine rejection; sea ice cover can then inhibit air-sea gas exchange resulting in winter mixed layers that are super-saturated. Decreasing mixed layer O<sub>2</sub> concentrations and saturation levels are observed during winter months between 2007 and 2019 in the Canada Basin. Only a minor portion of the decreasing trend in wintertime O<sub>2</sub> can be attributed to decreased solubility. This suggests the O<sub>2</sub> decline may be linked to more efficient air-sea exchange associated with increased open water areas in the winter sea ice pack that are not necessarily detectable via satellite observations.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Quantifying Drivers of Seasonal and Interannual Variability of Dissolved Oxygen in the Canada Basin Mixed Layer\",\"authors\":\"Ashley Arroyo, Mary-Louise Timmermans, Mike DeGrandpre\",\"doi\":\"10.1029/2024JC020903\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Analysis of dissolved oxygen (O<sub>2</sub>) in the Arctic's surface ocean provides insights into gas transfer between the atmosphere-ice-ocean system, water mass dynamics, and biogeochemical processes. In the Arctic Ocean's Canada Basin mixed layer, higher O<sub>2</sub> concentrations are generally observed under sea ice compared to open water regions. Annual cycles of O<sub>2</sub> and O<sub>2</sub> saturation, increasing from summer through spring and then sharply declining to late summer, are tightly linked to sea ice cover. The primary fluxes that influence seasonal variability of O<sub>2</sub> are modeled and compared to Ice-Tethered Profiler O<sub>2</sub> observations to understand the relative role of each flux in the annual cycle. Findings suggest that sea ice melt/growth dominates seasonal variations in mixed layer O<sub>2</sub>, with minor contributions from vertical entrainment and atmospheric exchange. While the influence of biological activity on O<sub>2</sub> variability cannot be directly assessed, indirect evidence suggests relatively minor contributions, although with significant uncertainty. Past studies show that O<sub>2</sub> molecules are expelled from sea ice during brine rejection; sea ice cover can then inhibit air-sea gas exchange resulting in winter mixed layers that are super-saturated. Decreasing mixed layer O<sub>2</sub> concentrations and saturation levels are observed during winter months between 2007 and 2019 in the Canada Basin. Only a minor portion of the decreasing trend in wintertime O<sub>2</sub> can be attributed to decreased solubility. This suggests the O<sub>2</sub> decline may be linked to more efficient air-sea exchange associated with increased open water areas in the winter sea ice pack that are not necessarily detectable via satellite observations.</p>\",\"PeriodicalId\":54340,\"journal\":{\"name\":\"Journal of Geophysical Research-Oceans\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.3000,\"publicationDate\":\"2024-07-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Geophysical Research-Oceans\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1029/2024JC020903\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"OCEANOGRAPHY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Geophysical Research-Oceans","FirstCategoryId":"89","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1029/2024JC020903","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"OCEANOGRAPHY","Score":null,"Total":0}
Quantifying Drivers of Seasonal and Interannual Variability of Dissolved Oxygen in the Canada Basin Mixed Layer
Analysis of dissolved oxygen (O2) in the Arctic's surface ocean provides insights into gas transfer between the atmosphere-ice-ocean system, water mass dynamics, and biogeochemical processes. In the Arctic Ocean's Canada Basin mixed layer, higher O2 concentrations are generally observed under sea ice compared to open water regions. Annual cycles of O2 and O2 saturation, increasing from summer through spring and then sharply declining to late summer, are tightly linked to sea ice cover. The primary fluxes that influence seasonal variability of O2 are modeled and compared to Ice-Tethered Profiler O2 observations to understand the relative role of each flux in the annual cycle. Findings suggest that sea ice melt/growth dominates seasonal variations in mixed layer O2, with minor contributions from vertical entrainment and atmospheric exchange. While the influence of biological activity on O2 variability cannot be directly assessed, indirect evidence suggests relatively minor contributions, although with significant uncertainty. Past studies show that O2 molecules are expelled from sea ice during brine rejection; sea ice cover can then inhibit air-sea gas exchange resulting in winter mixed layers that are super-saturated. Decreasing mixed layer O2 concentrations and saturation levels are observed during winter months between 2007 and 2019 in the Canada Basin. Only a minor portion of the decreasing trend in wintertime O2 can be attributed to decreased solubility. This suggests the O2 decline may be linked to more efficient air-sea exchange associated with increased open water areas in the winter sea ice pack that are not necessarily detectable via satellite observations.