DOI: 10.1175/JCLI-D-15-0710.1
Scopus记录号: 2-s2.0-84993993767
论文题名: Seasonal and interannual variations of the energy flux equator and ITCZ. Part II: Zonally varying shifts of the ITCZ
作者: Adam O. ; Bischoff T. ; Schneider T.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2016
卷: 29, 期: 20 起始页码: 7281
结束页码: 7293
语种: 英语
Scopus关键词: Atmospheric thermodynamics
; Budget control
; Climatology
; Meteorology
; Nickel
; Atmosphere-ocean interactions
; Atmospheric circulation
; Energy budget/balance
; ENSO
; Meridional overturning circulations
; Atmospheric movements
; air-sea interaction
; annual variation
; atmospheric circulation
; El Nino-Southern Oscillation
; energy flux
; intertropical convergence zone
; meridional circulation
; seasonal variation
; Pacific Ocean
英文摘要: The ITCZ lies at the ascending branch of the tropical meridional overturning circulation, where near-surface meridional mass fluxes vanish. Near the ITCZ, column-integrated energy fluxes vanish, forming an atmospheric energy flux equator (EFE). This paper extends existing approximations relating the ITCZ position and EFE to the atmospheric energy budget by allowing for zonal variations. The resulting relations are tested using reanalysis data for 1979-2014. The zonally varying EFE is found as the latitude where the meridional component of the divergent atmospheric energy transport (AET) vanishes. A Taylor expansion of the AET around the equator relates the ITCZ position to derivatives of the AET. To a first order, the ITCZ position is proportional to the divergent AET across the equator; it is inversely proportional to the local atmospheric net energy input (NEI) that consists of the net energy fluxes at the surface, at the top of the atmosphere, and zonally across longitudes. The first-order approximation captures the seasonal migrations of the ITCZ in the African, Asian, and Atlantic sectors. In the eastern Pacific, a third-order approximation captures the bifurcation from single- to double-ITCZ states that occurs during boreal spring. In contrast to linear EFE theory, during boreal winter in the eastern Pacific, northward cross-equatorial AET goes along with an ITCZ north of the equator. EFE and ITCZ variations driven by ENSO are characterized by an equatorward (poleward) shift in the Pacific during El Niño (La Niña) episodes, which are associated with variations in equatorial ocean energy uptake. © 2016 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50196
Appears in Collections: 气候变化事实与影响
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作者单位: ETH Zürich, Zurich, Switzerland; California Institute of Technology, Pasadena, CA, United States
Recommended Citation:
Adam O.,Bischoff T.,Schneider T.. Seasonal and interannual variations of the energy flux equator and ITCZ. Part II: Zonally varying shifts of the ITCZ[J]. Journal of Climate,2016-01-01,29(20)