Optimal Perturbations Triggering Weather Regime Transitions:Onset of Blocking and Strong Zonal Flow

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	Optimal Perturbations Triggering Weather Regime Transitions:Onset of Blocking and Strong Zonal Flow
	Jiang ZN(姜智娜); Mu M(穆穆); Wang DH(王东海)
发表期刊	Advances in Atmospheric Sciences
ISSN	0256-1530
	2011-01-15
出版年	2011
卷号	v.28 期号:01 页码:61-70
文献类型	CNKI期刊论文
摘要	In this paper, the approach proposed by Mu and Jiang (2008) to obtain the optimal perturbations for triggering blocking (BL) onset is generalized to seek the optimal perturbations triggering onset of the strong zonal flow (SZF) regime. The BL and SZF regimes are characterized by the same dipole-like anomaly pattern superposed on the climatological flow, but with opposite sign. The results show that this method is also superior at finding the initial optimal perturbations triggering onset of the SZF regime, especially in the medium range. Furthermore, by comparing the two kinds of conditional nonlinear optimal perturbations (CNOPs) trig-gering onset of BL and SZF regimes, we find that in the linear approximation, there is symmetry in the sensitivities for BL and SZF onset, and the perturbations that optimally trigger onset of BL and SZF regimes at times when linear approximation is valid are also characterized by the same spatial pattern but with opposite sign. Whereas when the optimization time is extended to 6 days, the two kinds of CNOPs lose their out-of-phase behavior. The nonlinearity results in an asymmetry between the sensitivity for BL and SZF onset. Additionally, we find that the optimal perturbations have one common property, which is that the second baroclinic mode contributes more to the initial perturbations while the barotropic mode dominates the final structures.
关键词	linear approximation, symmetry, nonlinearity, asymmetry
CNKI专辑号	A;
CNKI专辑名称	基础科学;
CNKI专题号	A009
CNKI专题名称	气象学;
分类号	P433.2
收录类别	中科院核心
语种	英文;
资助项目(基金）	supported by the National Natural Science Foundation of China (Grant Nos 40905023 and 40633016) ; the State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences Program for Basic Research of China (No2008LASWZI01)
文献类型	CNKI期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/191814
专题	中国科学院海洋研究所
作者单位	1.StateKeyLaboratoryofSevereWeather,ChineseAcademyofMeteorologicalSciences 2.KeyLaboratoryofOceanCirculationandWave,InstituteofOceanology,ChineseAcademyofSciences 3.StateKeyLaboratoryofNumericalModelingforAtmosphericSciencesandGeophysicalFluidDynamics,InstituteofAtmosphericPhysics,ChineseAcademyofSciences
推荐引用方式 GB/T 7714	Jiang ZN,Mu M,Wang DH. Optimal Perturbations Triggering Weather Regime Transitions:Onset of Blocking and Strong Zonal Flow. 2011.