DOI: 10.1175/JCLI-D-16-0360.1
Scopus记录号: 2-s2.0-85015872258
论文题名: Effects of the South Asian monsoon intraseasonal modes on genesis of low pressure systems over Bangladesh
作者: Hatsuzuka D. ; Fujinami H.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2017
卷: 30, 期: 7 起始页码: 2481
结束页码: 2499
语种: 英语
Scopus关键词: Climate change
; Climatology
; Meteorology
; Rain
; Storms
; Vorticity
; Anticyclonic anomalies
; Atmospheric circulation
; Boreal summer intraseasonal oscillation
; Environmental conditions
; Intraseasonal variability
; Low pressure systems
; Monsoons
; Tropical cyclone
; Atmospheric thermodynamics
; anticyclone
; atmospheric circulation
; atmospheric convection
; environmental conditions
; low pressure system
; monsoon
; tropical cyclone
; Bangladesh
; Bay of Bengal
; Indian Ocean
; Pacific Ocean
; Pacific Ocean (West)
英文摘要: The quasi-biweekly oscillation (QBW) is a dominant intraseasonal mode in summer rainfall over Bangladesh. Active phases of the QBW are often accompanied by low pressure systems (LPSs) such as vortex-type lows. This study investigated the effects of two intraseasonal modes, the QBW and the boreal summer intraseasonal oscillation (BSISO), on the genesis of LPSs over Bangladesh during 29 summer monsoon seasons. Daily lag composites of convection and low-level atmospheric circulation were constructed for active-phase cases with LPSs (LPS case) and without LPSs (non-LPS case) based on rainfall in the QBW over Bangladesh. In the QBW mode, a westward propagation of an anticyclonic anomaly from the western Pacific to the Bay of Bengal (BoB) is common in both cases. However, the anticyclonic center in the LPS case is located slightly to the east of that in the non-LPS case, which results in stronger cyclonic vorticity over and around Bangladesh. In contrast, the BSISO mode shows an opposite phase between the two cases: a cyclonic (anticyclonic) anomaly propagating northward from the equator to the BoB in the LPS case (non-LPS case). In the LPS case, the cyclonic anomaly in the BSISO mode enhances the westerly (easterly) flow over the BoB (Bangladesh) in the active phase, resulting in the enhancement of cyclonic vorticity over the northern BoB and Bangladesh, in cooperation with the QBW mode. These results suggest that both the QBW and BSISO modes have significant influence on the environmental conditions for LPS genesis over Bangladesh. © 2017 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49804
Appears in Collections: 气候变化事实与影响
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作者单位: Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan; Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan; Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
Recommended Citation:
Hatsuzuka D.,Fujinami H.. Effects of the South Asian monsoon intraseasonal modes on genesis of low pressure systems over Bangladesh[J]. Journal of Climate,2017-01-01,30(7)