Optimal nonlinear excitation of decadal variability of the North Atlantic thermohaline circulation

IOCAS-IR

	Optimal nonlinear excitation of decadal variability of the North Atlantic thermohaline circulation
	Zu ZQ(祖子清); Mu M(穆穆); Henk A.DIJKSTRA
发表期刊	Chinese Journal of Oceanology and Limnology
ISSN	0254-4059
	2013-11-15
出版年	2013
卷号	v.31 期号:06 页码:196-202
文献类型	CNKI期刊论文
摘要	Nonlinear development of salinity perturbations in the Atlantic thermohaline circulation(THC) is investigated with a three-dimensional ocean circulation model,using the conditional nonlinear optimal perturbation method.The results show two types of optimal initial perturbations of sea surface salinity,one associated with freshwater and the other with salinity.Both types of perturbations excite decadal variability of the THC.Under the same amplitude of initial perturbation,the decadal variation induced by the freshwater perturbation is much stronger than that by the salinity perturbation,suggesting that the THC is more sensitive to freshwater than salinity perturbation.As the amplitude of initial perturbation increases,the decadal variations become stronger for both perturbations.For salinity perturbations,recovery time of the THC to return to steady state gradually saturates with increasing amplitude,whereas this recovery time increases remarkably for freshwater perturbations.A nonlinear(advective) feedback between density and velocity anomalies is proposed to explain these characteristics of decadal variability excitation.The results are consistent with previous ones from simple box models,and highlight the importance of nonlinear feedback in decadal THC variability.
关键词	thermohaline circulation decadal variability conditional nonlinear optimal perturbation nonlinear advective feedback
CNKI专辑号	A;
CNKI专辑名称	基础科学;
CNKI专题号	A010;
CNKI专题名称	海洋学;
分类号	P731
收录类别	中科院核心 ; 中科院扩展
语种	英文;
资助项目(基金）	Supported by the National Basic Research Program of China(973 Program)(No.2012CB417404)
文献类型	CNKI期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/190667
专题	中国科学院海洋研究所
作者单位	1.LASG,InstituteofAtmosphericPhysics,ChineseAcademyofSciences 2.UniversityofChineseAcademyofSciences 3.KeyLaboratoryofOceanCirculationandWave,InstituteofOceanology,ChineseAcademyofSciences 4.InstituteforMarineandAtmosphericResearchUtrecht,DepartmentofPhysicsandAstronomy,UtrechtUniversity
推荐引用方式 GB/T 7714	Zu ZQ,Mu M,Henk A.DIJKSTRA. Optimal nonlinear excitation of decadal variability of the North Atlantic thermohaline circulation. 2013.