DOI: 10.1002/jgrd.50418
论文题名: The importance of the tropical tropopause layer for equatorial Kelvin wave propagation
作者: Flannaghan T.J. ; Fueglistaler S.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 11 起始页码: 5160
结束页码: 5175
语种: 英语
英文关键词: Kelvin waves
; Ray tracing
; Tropical Tropopause Layer
; UTLS
Scopus关键词: Climate change
; Clouds
; Data flow analysis
; Gravity waves
; Ionosphere
; Ray tracing
; Tropics
; Troposphere
; Wave propagation
; Constellation observing system for meteorology , ionosphere , and climates
; Interannual variability
; Kelvin wave propagation
; Kelvin waves
; Ray tracing calculations
; Seasonal and interannual variability
; Tropical tropopause layers
; UTLS
; Coastal zones
; annual variation
; El Nino-Southern Oscillation
; Kelvin wave
; ray tracing
; stratosphere
; tropopause
; troposphere
; wave propagation
; wave velocity
; zonal wind
英文摘要: We analyze the propagation of equatorial Kelvin waves from the troposphere to the stratosphere using a new filtering technique applied to ERA-Interim data (very similar results for Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) temperatures) that allows separation of wave activity into number of waves and wave amplitude. The phase speed of Kelvin waves (order 20 m/s) is similar to the magnitude of zonal wind in the tropical tropopause layer (TTL), and correspondingly, we find that the seasonal and interannual variability of Kelvin wave propagation is dominated by the variability in the wind field and less by tropospheric convectively coupled wave activity. We show that local relations between wave activity and zonal wind are ambiguous, and only full ray tracing calculations can explain the observed patterns of wave activity. Easterlies amplify and deflect the eastward traveling waves upward. Westerlies have the opposite effect. During boreal winter, the strong dipole of zonal winds in the TTL centered at the dateline confines wave propagation into the stratosphere to a window over the Atlantic-Indian Ocean sector (30°W to 90°E), which casts a lasting "shadow" into the lower stratosphere that explains the remarkable zonal asymmetry in wave activity there. During boreal summer, the upper level monsoon circulation leads to maximum easterlies, and wave amplitude (but not number of waves) maximizes over the Indian Ocean sector (30°E to 90°E). Interannual variability in wave propagation due to El-Niño/Southern Oscillation, for example, is well explained by its modification of the zonal wind field. © 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/63679
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: Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Centre for Mathematical Sciences, Wilberforce Rd., Cambridge CB3 0WA, United Kingdom; Atmosphere and Ocean Sciences, Princeton University, Princeton, NJ, United States
Recommended Citation:
Flannaghan T.J.,Fueglistaler S.. The importance of the tropical tropopause layer for equatorial Kelvin wave propagation[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(11)