DOI: 10.1007/s00382-016-3215-3
Scopus记录号: 2-s2.0-84973664425
论文题名: Roles of convective heating and boundary-layer moisture asymmetry in slowing down the convectively coupled Kelvin waves
作者: Wang L. ; Li T.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2017
卷: 48, 期: 2017-07-08 起始页码: 2453
结束页码: 2469
语种: 英语
英文关键词: Ekman pumping
; Indian Ocean
; Kelvin wave
; Planetary boundary layer
; Theoretical model
英文摘要: Mechanisms for an in-phase relationship between convection and low-level zonal wind and the slow propagation of the convectively coupled Kelvin wave (CCKW) are investigated by analyzing satellite-based brightness temperature and reanalysis data and by constructing a simple theoretical model. Observational data analysis reveals an eastward shift of the low-level convergence and moisture relative to the CCKW convective center. The composite vertical structures show that the low-level convergence lies in the planetary boundary layer (PBL) (below 800 hPa), and is induced by the pressure trough above the top of PBL through an Ekman-pumping process. A traditional view of a slower eastward propagation speed compared to the dry Kelvin waves is attributed to the reduction of atmospheric static stability in mid-troposphere due to the convective heating effect. The authors’ quantitative assessment of the heating effect shows that this effect alone cannot explain the observed CCKW phase speed. We hypothesize that additional slowing process arises from the effect of zonally asymmetric PBL moisture. A simple theoretical model is constructed to understand the relative role of the heating induced effective static stability effect and the PBL moisture effect. The result demonstrates the important role of the both effects. Thus, PBL-free atmosphere interaction is important in explaining the observed structure and propagation of CCKW. © 2016, Springer-Verlag Berlin Heidelberg. 资助项目: NSFC, National Natural Science Foundation of China
; ONR, Office of Naval Research
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53269
Appears in Collections: 过去全球变化的重建
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作者单位: Key Laboratory of Meteorological Disaster, Ministry of Education (KLME)/Joint International Research Laboratory of Climate and Environmental Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science and Technology, Nanjing, China; International Pacific Research Center, and School of Ocean and Earth Science and Technology, University of Hawaii, 2525 Correa Rd., Honolulu, HI, United States
Recommended Citation:
Wang L.,Li T.. Roles of convective heating and boundary-layer moisture asymmetry in slowing down the convectively coupled Kelvin waves[J]. Climate Dynamics,2017-01-01,48(2017-07-08)