Characterization of double diffusive convection steps and heat budget in the deep Arctic Ocean

CORC > 南海海洋研究所 > 中国科学院南海海洋研究所 > 热带海洋环境国家重点实验室(LTO)

	Characterization of double diffusive convection steps and heat budget in the deep Arctic Ocean
	[Zhou, Sheng-Qi ; Lu, Yuan-Zheng] Chinese Acad Sci, State Key Lab Trop Oceanog, South China Sea Inst Oceanol, Guangzhou 510301, Guangdong, Peoples R China ; [Lu, Yuan-Zheng] Univ Chinese Acad Sci, Beijing 100049, Peoples R China
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
	2013
卷号	118 期号:12 页码:6672-6686
关键词	double diffusive convection geothermal heating diapycnal mixing turbulent behavior
ISSN号	2169-9275
通讯作者	sqzhou@scsio.ac.cn
中文摘要	In this paper, we explore the hydrographic structure and heat budget in the deep Canada Basin by using data measured with McLane-Moored-Profilers (MMP), bottom pressure recorders (BPR), and conductivity-temperature-depth (CTD) profilers. Upward from the bottom, a homogeneous bottom layer and its overlaying double diffusive convection (DDC) steps are well identified at Mooring A ( 75 degrees N,150 degrees W). We find that the deep water is in weak diapycnal mixing because the effective diffusivity of the bottom layer is approximate to 1.8x10-5m2s-1, while that of the other steps is approximate to 10-6m2s-1. The vertical heat flux through the DDC steps is evaluated by using different methods. We find that the heat flux ( 0.1-11mWm-2) is much smaller than geothermal heating ( approximate to 50mWm-2). This suggests that the stack of DDC steps acts as a thermal barrier in the deep basin. Moreover, the temporal distributions of temperature and salinity differences across the interface are exponential, whereas those of heat flux and effective diffusivity are found to be approximately lognormal. Both are the result of strong intermittency. Between 2003 and 2011, temperature fluctuations close to the sea floor were distributed asymmetrically and skewed toward positive values, which provide a direct observation that geothermal heating was transferred into the ocean. Both BPR and CTD data suggest that geothermal heating and not the warming of the upper ocean is the dominant mechanism responsible for the warming of deep water. As the DDC steps prevent vertical heat transfer, geothermal heating is unlikely to have a significant effect on the middle and upper Arctic Ocean.
学科主题	Oceanography
资助信息	We gratefully acknowledge Mary-Louise Timmermans for her support and generosity in sharing valuable communications of data set and BPR measurements. We thank Martin Schmid for sending the data of Lake Kivu for comparison. We are grateful to Rui Xin Huang and Raymond W. Schmitt for the helpful discussions on geothermal heating and double diffusive convection. We specially thank Zuojun Yu for the valuable comments. We also thank the anonymous reviewers for helpful suggestions. This work was supported by China NSF grants (41176027 and 11072253), Guangdong NSF grant (10251030101000000), and the 973 Program grant (2010CB950302). The data were collected and made available by the Beaufort Gyre Exploration Program based at the Woods Hole Oceanographic Institution (http://www.whoi.edu/beaufortgyre) in collaboration with researchers from the Fisheries and Oceans Canada at the Institute of Ocean Sciences.
原文出处	AMER GEOPHYSICAL UNION
语种	英语
WOS记录号	WOS:000329926200024
公开日期	2015-01-14
内容类型	期刊论文
源URL	[http://ir.scsio.ac.cn/handle/344004/10861]
专题	南海海洋研究所_热带海洋环境国家重点实验室(LTO)
推荐引用方式 GB/T 7714	[Zhou, Sheng-Qi,Lu, Yuan-Zheng] Chinese Acad Sci, State Key Lab Trop Oceanog, South China Sea Inst Oceanol, Guangzhou 510301, Guangdong, Peoples R China,[Lu, Yuan-Zheng] Univ Chinese Acad Sci, Beijing 100049, Peoples R China. Characterization of double diffusive convection steps and heat budget in the deep Arctic Ocean[J]. JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS,2013,118(12):6672-6686.
APA	[Zhou, Sheng-Qi,Lu, Yuan-Zheng] Chinese Acad Sci, State Key Lab Trop Oceanog, South China Sea Inst Oceanol, Guangzhou 510301, Guangdong, Peoples R China,&[Lu, Yuan-Zheng] Univ Chinese Acad Sci, Beijing 100049, Peoples R China.(2013).Characterization of double diffusive convection steps and heat budget in the deep Arctic Ocean.JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS,118(12),6672-6686.
MLA	[Zhou, Sheng-Qi,et al."Characterization of double diffusive convection steps and heat budget in the deep Arctic Ocean".JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS 118.12(2013):6672-6686.