Effect of low-frequency Rossby wave on thermal structure of the upper southwestern tropical Indian Ocean

IOCAS-IR

	Effect of low-frequency Rossby wave on thermal structure of the upper southwestern tropical Indian Ocean
	Feng JQ(冯俊乔); Bai XZ(白学志); Chen YL(陈永利); Hu DX(胡敦欣)
发表期刊	Chinese Journal of Oceanology and Limnology
ISSN	0254-4059
	2010-04-15
出版年	2010
卷号	v.28 期号:02 页码:146-155
文献类型	CNKI期刊论文
摘要	We investigate the influence of low-frequency Rossby waves on the thermal structure of the upper southwestern tropical Indian Ocean (SWTIO) using Argo profiles, satellite altimetric data, sea surface temperature, wind field data and the theory of linear vertical normal mode decomposition. Our results show that the SWTIO is generally dominated by the first baroclinic mode motion. As strong downwelling Rossby waves reach the SWTIO, the contribution of the second baroclinic mode motion in this region can be increased mainly because of the reduction in the vertical stratification of the upper layer above thermocline, and the enhancement in the vertical stratification of the lower layer under thermocline also contributes to it. The vertical displacement of each isothermal is enlarged and the thermal structure of the upper level is modulated, which is indicative of strong vertical mixing. However, the cold Rossby waves increase the vertical stratification of the upper level, restricting the variability related to the second baroclinic mode. On the other hand, during decaying phase of warm Rossby waves, Ekman upwelling and advection processes associated with the surface cyclonic wind circulation can restrain the downwelling processes, carrying the relatively colder water to the near-surface, which results in an out-of-phase phenomenon between sea surface temperature anomaly (SSTA) and sea surface height anomaly (SSHA) in the SWTIO.
关键词	Rossby wave vertical baroclinic mode Argo sea surface height anomaly (SSHA) sea surface temperature anomaly (SSTA)
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
语种	英文;
资助项目(基金）	Supported by the National Natural Science Foundation of China (Nos. 40776013, 40306006) ; the State Key Basic Research Development Project (Nos. 2007CB411802, 2006CB403603)
文献类型	CNKI期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/192163
专题	中国科学院海洋研究所
作者单位	1.InstituteofOceanology,ChineseAcademyofSciences 2.KeyLaboratoryofOceanCirculationandWaves,ChineseAcademyofSciences 3.GraduateUniversityofChineseAcademyofSciences
推荐引用方式 GB/T 7714	Feng JQ,Bai XZ,Chen YL,et al. Effect of low-frequency Rossby wave on thermal structure of the upper southwestern tropical Indian Ocean. 2010.