DOI: 10.1175/JCLI-D-17-0723.1
Scopus记录号: 2-s2.0-85047062289
论文题名: The role of the water vapor feedback in the ITCZ response to hemispherically asymmetric forcings
作者: Clark S.K. ; Ming Y. ; Held I.M. ; Phillipps P.J.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2018
卷: 31, 期: 9 起始页码: 3659
结束页码: 3678
语种: 英语
英文关键词: Energy budget/balance
; Hadley circulation
; Hydrologic cycle
; Water vapor
Scopus关键词: Budget control
; Feedback
; Radiative transfer
; Water absorption
; Energy budget/balance
; General circulation model
; Hadley circulation
; Hydrologic cycles
; Intertropical convergence zone
; Radiative transfer codes
; Water vapor feedbacks
; Water-vapor absorption
; Water vapor
英文摘要: In comprehensive and idealized general circulation models, hemispherically asymmetric forcings lead to shifts in the latitude of the intertropical convergence zone (ITCZ). Prior studies using comprehensive GCMs (with complicated parameterizations of radiation, clouds, and convection) suggest that the water vapor feedback tends to amplify the movement of the ITCZ in response to a given hemispherically asymmetric forcing, but this effect has yet to be elucidated in isolation. This study uses an idealized moist model, coupled to a full radiative transfer code, but without clouds, to examine the role of the water vapor feedback in a targeted manner. In experiments with interactive water vapor and radiation, the ITCZ latitude shifts roughly twice as much off the equator as in cases with the water vapor field seen by the radiation code prescribed to a static hemisperically symmetric control distribution. Using energy flux equator theory for the latitude of the ITCZ, the amplification of the ITCZ shift is attributed primarily to the longwave water vapor absorption associated with the movement of the ITCZ into the warmer hemisphere, further increasing the net column heating asymmetry. Local amplification of the imposed forcing by the shortwave water vapor feedback plays a secondary role. Experiments varying the convective relaxation time, an important parameter in the convection scheme used in the idealized moist model, yield qualitatively similar results, suggesting some degree of robustness to the model physics; however, the sensitivity experiments do not preclude that more extreme modifications to the convection scheme could lead to qualitatively different behavior. © 2018 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/111560
Appears in Collections: 气候减缓与适应
There are no files associated with this item.
作者单位: Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ, United States; NOAA/Geophysical Fluid Dynamics Laboratory, Princeton, NJ, United States
Recommended Citation:
Clark S.K.,Ming Y.,Held I.M.,et al. The role of the water vapor feedback in the ITCZ response to hemispherically asymmetric forcings[J]. Journal of Climate,2018-01-01,31(9)