DOI: 10.1002/jgrd.502812013
论文题名: Intraseasonal variations in the tropical tropopause temperature revealed by cluster analysis of convective activity
作者: Nishimoto E. ; Shiotani M.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 9 起始页码: 3545
结束页码: 3556
语种: 英语
Scopus关键词: Atmospheric pressure
; Clouds
; Cluster analysis
; Dehydration
; Tropical engineering
; Tropics
; Weather forecasting
; Wind effects
; European centre for medium-range weather forecasts
; Intraseasonal oscillations
; Intraseasonal variations
; National Oceanic and Atmospheric Administration
; Outgoing longwave radiation
; Temperature structure
; Tropical convective activity
; Tropical tropopause
; Atmospheric temperature
; cluster analysis
; convective system
; dehydration
; El Nino-Southern Oscillation
; La Nina
; longwave radiation
; sea surface temperature
; seasonal variation
; temperature effect
; tropopause
; weather forecasting
英文摘要: Space-time variations of the tropical convective activities and temperatures around the tropical tropopause associated with the intraseasonal oscillation (ISO) are investigated using outgoing longwave radiation (OLR) data from the National Oceanic and Atmospheric Administration and atmospheric fields from the European Centre for Medium-range Weather Forecasts Interim reanalysis data. By performing cluster analysis using the locus of convective activities observed in the unfiltered OLR field, the 72 ISO events selected during the southern summers from 1979-2011 are mainly grouped into four clusters. Two of the clusters exhibit the slow (<2 m/s) propagation speed in the unfiltered OLR field and the others fast (4 m/s). One cluster characterized as the El Niño phase has the fast speed while passing over the date line and another as the La Niña phase has the slow speed while propagating to 120?E. Compared with the other two clusters characterized as the weak El Niño-Southern Oscillation phase, the speed is slow while propagating to 135?E when the SSTs over the Western Pacific are relatively low. Low temperatures around the tropical tropopause appear to the east of the eastward-propagating convection in the tropics and to the west in the subtropics, forming a horseshoe-shaped structure. The strength of the horseshoe-shaped temperature structure is determined by that of the convective activities. Furthermore, the strength and location of the 100 hPa temperature minima differ among the clusters. This study implies that the different ISOs would cause different impacts on the dehydration process depending on their types. © 2013. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63453
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
Recommended Citation:
Nishimoto E.,Shiotani M.. Intraseasonal variations in the tropical tropopause temperature revealed by cluster analysis of convective activity[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(9)