DOI: 10.1175/JCLI-D-17-0127.1
Scopus记录号: 2-s2.0-85028518106
论文题名: Untangling the annual cycle of the tropical tropopause layer with an idealized moist model
作者: Jucker M. ; Gerber E.P.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2017
卷: 30, 期: 18 起始页码: 7339
结束页码: 7358
语种: 英语
Scopus关键词: Clouds
; Dynamics
; Fighter aircraft
; Mechanical waves
; Meteorology
; Transistor transistor logic circuits
; Upper atmosphere
; Water vapor
; Brewer-Dobson circulation
; General circulation model
; Intermediate complexity
; Northern Hemispheres
; Seasonal cycle
; Stratosphere-troposphere coupling
; Tropical tropopause layers
; Tropical variability
; Tropics
英文摘要: The processes regulating the climatology and annual cycle of the tropical tropopause layer (TTL) and cold point are not fully understood. Three main drivers have been identified: planetary-scale equatorial waves excited by tropical convection, planetary-scale extratropical waves associated with the deep Brewer-Dobson circulation, and synoptic-scale waves associated with the midlatitude storm tracks. In both observations and comprehensive atmospheric models, all three coexist, making it difficult to separate their contributions. Here, a new intermediate-complexity atmospheric model is developed. Simple modification of the model's lower boundary allows detailed study of the three processes key to the TTL, both in isolation and together. The model shows that tropical planetary waves are most critical for regulating the mean TTL, setting the depth and temperature of the cold point. The annual cycle of the TTL, which is coldest (warmest) in boreal winter (summer), however, depends critically on the strong annual variation in baroclinicity of the Northern Hemisphere relative to that of the Southern Hemisphere. Planetary-scale waves excited from either the tropics or extratropics then double the impact of baroclinicity on the TTL annual cycle. The remarkably generic response of TTL temperatures over a range of configurations suggests that the details of the wave forcing are unimportant, provided there is sufficient variation in the upward extent of westerly winds over the annual cycle. Westerly winds enable the propagation of stationary Rossby waves, and weakening of the subtropical jet in boreal summer inhibits their propagation into the lower stratosphere, warming the TTL. © 2017 American Meteorological Society. 资助项目: NSF, National Science Foundation
; NSF, National Science Foundation
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/48722
Appears in Collections: 气候减缓与适应 气候变化与战略
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作者单位: Courant Institute of Mathematical Sciences, New York University, New York, NY, United States; School of Earth Sciences, Centre of Excellence for Climate System Science, The University of Melbourne, Australia
Recommended Citation:
Jucker M.,Gerber E.P.. Untangling the annual cycle of the tropical tropopause layer with an idealized moist model[J]. Journal of Climate,2017-01-01,30(18)