气候变化领域集成服务门户(CCPortal): Temporal Changes in the Causes of the Observed Oxygen Decline in the St. Lawrence Estuary

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DOI	10.1029/2020JC016577
	Temporal Changes in the Causes of the Observed Oxygen Decline in the St. Lawrence Estuary
	Jutras M.; Dufour C.O.; Mucci A.; Cyr F.; Gilbert D.
发表日期	2020
ISSN	21699275
卷号	125 期号:12
英文摘要	Oxygen concentrations in the deep waters of the Lower St. Lawrence Estuary have decreased by 50% over the past century. The drivers of this decrease are investigated by applying an extended Optimum Multiparameter analysis to a time series of physical and biogeochemical observations of the St. Lawrence Estuarine System in the 1970s and from late 1990s to 2018. This method reconstructs the relative contributions of the two major water masses feeding the system, the Labrador Current Waters (LCW) and the North Atlantic Central Waters (NACW), as well as oxygen utilization, and accounts for diapycnal mixing. The causes of the oxygen decline varied over the last 5 decades. Between the 1970s and late 1990s, the decrease was mainly driven by biogeochemical changes through an increase in microbial oxygen utilization in the St. Lawrence Estuary in response to warmer temperatures and eutrophication and lower oxygen concentrations in LCW and NACW. Between 2008 and 2018, the decrease was mainly driven by circulation changes in the western North Atlantic associated with a reduced inflow of high-oxygenated LCW to the deep waters of the system in favor of low-oxygenated NACW, reaching a historical minimum in 2016. The LCW:NACW ratio is strongly correlated with the volume transport of the Scotian shelf-break current, an extension of the Labrador Current. These results highlight the primary role of the Labrador Current in determining the oxygen concentration and other water properties of the St. Lawrence Estuarine System and on the western North Atlantic continental shelf and slope. © 2020. American Geophysical Union. All Rights Reserved.
英文关键词	deoxygenation; eutrophication; Labrador Current; oxygen; slope waters; St. Lawrence Estuary
语种	英语
来源期刊	Journal of Geophysical Research: Oceans
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186538
作者单位	Department of Earth and Planetary Sciences, McGill University, Montreal, QC, Canada; Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, QC, Canada; Geotop, Université du Québec à Montréal, Montreal, QC, Canada; Northwest Atlantic Fisheries Centre, Fisheries and Oceans Canada, St. John's, NL, Canada; Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, NL, Canada; Maurice-Lamontagne Institute, Fisheries and Oceans Canada, Mont-Joli, QC, Canada
推荐引用方式 GB/T 7714	Jutras M.,Dufour C.O.,Mucci A.,et al. Temporal Changes in the Causes of the Observed Oxygen Decline in the St. Lawrence Estuary[J],2020,125(12).
APA	Jutras M.,Dufour C.O.,Mucci A.,Cyr F.,&Gilbert D..(2020).Temporal Changes in the Causes of the Observed Oxygen Decline in the St. Lawrence Estuary.Journal of Geophysical Research: Oceans,125(12).
MLA	Jutras M.,et al."Temporal Changes in the Causes of the Observed Oxygen Decline in the St. Lawrence Estuary".Journal of Geophysical Research: Oceans 125.12(2020).