DOI: 10.1007/s00382-014-2222-5
Scopus记录号: 2-s2.0-84939890232
论文题名: Effects of rotation and mid-troposphere moisture on organized convection and convectively coupled gravity waves
作者: Majda A.J. ; Khouider B. ; Frenkel Y.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2014
卷: 44, 期: 2017-03-04 起始页码: 937
结束页码: 960
语种: 英语
英文关键词: Congestus clouds
; Convectively coupled waves
; Organized convection
; Rotation effects
; Stochastic parametrization
; Tropical circulation
英文摘要: Atmospheric convection has the striking capability to organize itself into a hierarchy of cloud clusters and super-clusters on scales ranging from the convective cell of a few kilometres to planetary scale disturbances such as the Madden–Julian oscillation. It is widely accepted that this phenomenon is due in large part to the two-way coupling between convective processes and equatorially trapped waves and planetary scale flows in general. However, the physical mechanisms responsible for this multiscale organization and the associated across-scale interactions are poorly understood. The two main peculiarities of the tropics are the vanishing of the Coriolis force at the equator and the abundance of mid-level moisture. Here we test the effect of these two physical properties on the organization of convection and its interaction with gravity waves in a simplified primitive equation model for flows parallel to the equator. Convection is represented by deterministic as well as stochastic multicloud models that are known to represent organized convection and convectively coupled waves quite well. It is found here that both planetary rotation and mid-troposphere moisture are important players in the diminishing of organized convection and convectively coupled gravity wave activity in the subtropics and mid-latitudes. The meridional mean circulation increases with latitude while the mean zonal circulation is much shallower and is dominated by mid-level jets, reminiscent of a second baroclinic mode circulation associated with a congestus mode instability in the model. This is consistent with the observed shallow Hadley and Walker circulations accompanied by congestus cloud decks in the higher latitude tropics and sub-tropics. Moreover, deep convection activity in the stochastic model simulations becomes very patchy and unorganized as the computational domain is pushed towards the subtropics and mid-latitudes. This is consistent with previous work based on cloud resolving modeling simulations on smaller domains. © 2014, Springer-Verlag Berlin Heidelberg. 资助项目: NSERC, Natural Sciences and Engineering Research Council of Canada
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54647
Appears in Collections: 过去全球变化的重建
There are no files associated with this item.
作者单位: Department of Mathematics and Center for Atmosphere-Ocean Science, Courant Institute, New York University, 251 Mercer Street, New York, NY, United States; Center for Prototype Climate Modeling, NYU Abu Dhabi Institute, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates; Department of Mathematics and Statistics, University of Victoria, PO BOX 3045 STN CSC, Victoria, BC, Canada
Recommended Citation:
Majda A.J.,Khouider B.,Frenkel Y.. Effects of rotation and mid-troposphere moisture on organized convection and convectively coupled gravity waves[J]. Climate Dynamics,2014-01-01,44(2017-03-04)