Scopus记录号: 2-s2.0-85047810508
论文题名: Subseasonal intensity variation of the South Asian high in relationship to diabatic heating: observation and CMIP5 models
作者: Shang W. ; Ren X. ; Huang B. ; Cubasch U. ; Yang X.-Q.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2019
卷: 52, 期: 2019-03-04 起始页码: 2413
结束页码: 2430
语种: 英语
英文关键词: CMIP5
; Diabatic heating
; South Asian high
; Subseasonal intensity variation
英文摘要: This study investigates the subseasonal intensity variation of South Asian high (SAH) and the dynamic linkage with precipitation induced diabatic heating during the summer of 1979–2005, based on the observation and 18 models from the Coupled Model Intercomparison Project (CMIP5). The SAH’s intensity variation with a period of approximately 10–36 days is identified both in the observation and 18 models, by performing an empirical orthogonal function (EOF) analysis on the standardized subseasonal anomalies in geopotential height at 100 hPa over the SAH’s main body region. With the observed strengthening of the SAH, an enhanced rainfall belt between 70°–120°E migrates northward from the equatorial region. The northward propagating rainfall belt occupies almost the whole Indian subcontinent, Indochina Peninsula and subtropical east Asian regions between 20°–40°N when the SAH reaches the strongest. The relative vorticity diagnosis reveals the dynamical linkage between the subseasonal SAH’s intensity variation and the precipitation anomalies over the Asian monsoon region: (1) The observed northward propagating rainfall band forms a horizontal gradient of diabatic heating, favoring an enhancement of the SAH over its southern part; (2) When the rainfall band approaches the regions of South and East Asia between 20°–40°N, the increased vertical gradient of diabatic heating in the upper level contributes significantly to the intensification of the SAH; (3) The horizontal advection process favors the westward expansion of the SAH. The observation-to-model comparisons indicate that the model’s capacity to reproduce the SAH’s intensity variation is highly associated with simulations of the anomalous rainfall band and its northward propagation. A realistic reproduction of precipitation anomalies is fundamental to simulating the dynamical processes related to diabatic heating, and thus the simulation of the SAH’s subseasonal intensity variation. © 2018, The Author(s). 资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/122393
Appears in Collections: 气候变化事实与影响
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作者单位: CMA-NJU Joint Laboratory for Climate Prediction Studies, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China; Industrial Ecology Programme, Department of Energy and Process Engineering, Norwegian University of Science and Technology, Trondheim, Norway; Institute of Meteorology, Freie Universität Berlin, Berlin, Germany
Recommended Citation:
Shang W.,Ren X.,Huang B.,et al. Subseasonal intensity variation of the South Asian high in relationship to diabatic heating: observation and CMIP5 models[J]. Climate Dynamics,2019-01-01,52(2019-03-04)