DOI: 10.1007/s00382-015-2661-7
Scopus记录号: 2-s2.0-84959104411
论文题名: Extratropical anticyclonic Rossby wave breaking and Indian summer monsoon failure
作者: Samanta D. ; Dash M.K. ; Goswami B.N. ; Pandey P.C.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2016
卷: 46, 期: 2017-05-06 起始页码: 1547
结束页码: 1562
语种: 英语
英文关键词: Blocking
; Indian summer monsoon
; Monsoonal convection
; Rossby wave breaking
英文摘要: Interactions between midlatitude disturbances and the monsoonal circulation are significant for the Indian summer monsoon (ISM) rainfall. This paper presents examples of monsoon–midlatitude linkage through anticyclonic Rossby wave breaking (RWB) over West Asia during June, July and August of the years 1998–2010. RWB events over West Asia are identified by the inversion of the potential vorticity air mass at three different isentropic levels (340, 350, and 360 K) using daily NCEP–NCAR reanalysis. It is observed that RWB took place over West Asia before/during breaks in the ISM. Further, these events occur on the anticyclonic shear side of the subtropical jet, where the gradient of the zonal wind is found to be high. RWB is responsible for the southward movement of high potential vorticity air from the westerly jet, leading to the formation of a blocking high over the Arabian region. In turn, this blocking high advects and causes the descent of upper tropospheric cold and dry air towards Central India. Such an air mass with low moist static energy inhibits deep monsoonal convection and thereby leads to a dry spell. In fact, we find that RWB induced blocking over West Asia to be one of the major causes of dry spell/break episodes in ISM. Additionally, the presence of cold air over Central India reduces the north–south thermal contrast over the monsoon region thereby modifying the local Hadley circulation over the region. © 2015, Springer-Verlag Berlin Heidelberg. 资助项目: NOAA, National Oceanic and Atmospheric Administration
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53791
Appears in Collections: 过去全球变化的重建
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作者单位: Centre for Oceans, Rivers, Atmosphere and Land Sciences, Indian Institute of Technology Kharagpur, Kharagpur, India; Earth and Climate Science Department, Indian Institute of Science Education and Research, Pune, India; School of Earth, Ocean and Climate Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar, India
Recommended Citation:
Samanta D.,Dash M.K.,Goswami B.N.,et al. Extratropical anticyclonic Rossby wave breaking and Indian summer monsoon failure[J]. Climate Dynamics,2016-01-01,46(2017-05-06)