气候变化领域集成服务门户(CCPortal): Mechanisms of Low-Frequency Oxygen Variability in the North Pacific

CCPortal

DOI	10.1029/2018GB005987
	Mechanisms of Low-Frequency Oxygen Variability in the North Pacific
	Ito T.; Long M.C.; Deutsch C.; Minobe S.; Sun D.
发表日期	2019
ISSN	0886-6236
EISSN	1944-9224
起始页码	110
结束页码	124
卷号	33 期号:2
英文摘要	This study investigates the mechanisms of interannual and decadal variability of dissolved oxygen (O 2 ) in the North Pacific using historical observations and a hindcast simulation using the Community Earth System Model. The simulated variability of upper ocean (200 m) O 2 is moderately correlated with observations where sampling density is relatively high. The dominant mode of O 2 variability explains 24.8% of the variance and is significantly correlated with the Pacific Decadal Oscillation (PDO) index (r = 0.68). Two primary mechanisms are hypothesized by which the PDO controls upper ocean O 2 variability. Vertical movement of isopycnals (“heave”) drives O 2 variations in the deep tropics; isopycnal surfaces are depressed in the eastern tropics under the positive (El Niño-like) phase of PDO, leading to O 2 increases in the upper water column. In contrast to the tropics, changes in subduction are the primary control on extratropical O 2 variability. These hypotheses are tested by contrasting O 2 anomalies with the heave-induced component of variability calculated from potential density anomalies. Isopycnal heave is the leading control on O 2 variability in the tropics, but heave alone cannot fully explain the amplitude of tropical O 2 variability, likely indicating reinforcing changes from the biological O 2 consumption. Midlatitude O 2 variability indeed reflects ocean ventilation downstream of the subduction region where O 2 anomalies are correlated with the depth of winter mixed layer. These mechanisms, synchronized with the PDO, yield a basin-scale pattern of O 2 variability that are comparable in magnitude to the projected rates of ocean deoxygenation in this century under “unchecked” emission scenario. ©2019. American Geophysical Union. All Rights Reserved.
英文关键词	biogeochemistry; CESM; climate variability; ocean deoxygenation; oxygen cycle; World Ocean Database
语种	英语
scopus关键词	annual variation; biogeochemistry; climate change; climate modeling; database; decadal variation; dissolved oxygen; hindcasting; mixed layer; Pacific Decadal Oscillation; sampling; simulation; upper ocean; ventilation; water column; Pacific Ocean; Pacific Ocean (North)
来源期刊	Global Biogeochemical Cycles
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/129750
作者单位	School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, United States; Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, CO, United States; School of Oceanography, University of Washington, Seattle, WA, United States; Department of Natural History Sciences, Graduate School of Science, Hokkaido University, Sapporo, Japan; Department of Earth and Planetary Sciences, Faculty of Science, Hokkaido University, Sapporo, Japan
推荐引用方式 GB/T 7714	Ito T.,Long M.C.,Deutsch C.,et al. Mechanisms of Low-Frequency Oxygen Variability in the North Pacific[J],2019,33(2).
APA	Ito T.,Long M.C.,Deutsch C.,Minobe S.,&Sun D..(2019).Mechanisms of Low-Frequency Oxygen Variability in the North Pacific.Global Biogeochemical Cycles,33(2).
MLA	Ito T.,et al."Mechanisms of Low-Frequency Oxygen Variability in the North Pacific".Global Biogeochemical Cycles 33.2(2019).