DOI: 10.1175/JCLI-D-11-00315.1
Scopus记录号: 2-s2.0-84858263700
论文题名: Tropical Atlantic Biases in CCSM4
作者: Grodsky S.A. ; Carton J.A. ; Nigam S. ; Okumura Y.M.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2012
卷: 25, 期: 11 起始页码: 3684
结束页码: 3701
语种: 英语
Scopus关键词: Atmosphere-ocean interactions
; Atmospheric components
; Community climate system model
; Coupled models
; Coupled simulation
; Horizontal resolution
; Marine stratocumulus clouds
; Mean sea level pressures
; Ocean model
; Oceanic components
; Polar lows
; Seasonal cycle
; Stratocumulus clouds
; Surface winds
; Tropical atlantic
; Atmospheric pressure
; Clouds
; Computer simulation
; Sea level
; Tropics
; Wind
; Climate models
; atmosphere-hydrosphere interaction
; atmospheric pressure
; climate modeling
; computer simulation
; parameterization
; sea level pressure
; sea surface temperature
; stratocumulus
; subtropical region
; surface wind
; twentieth century
; Africa
; Atlantic Ocean
; Atlantic Ocean (Tropical)
英文摘要: This paper focuses on diagnosing biases in the seasonal climate of the tropical Atlantic in the twentiethcentury simulation of the Community Climate System Model, version 4 (CCSM4). The biases appear in both atmospheric and oceanic components. Mean sea level pressure is erroneously high by a few millibars in the subtropical highs and erroneously low in the polar lows (similar to CCSM3). As a result, surface winds in the tropics are ~1 m s -1 too strong. Excess winds cause excess cooling and depressed SSTs north of the equator. However, south of the equator SST is erroneously high due to the presence of additional warming effects. The region of highest SST bias is close to southern Africa near the mean latitude of the Angola-Benguela Front (ABF). Comparison of CCSM4 to ocean simulations of various resolutions suggests that insufficient horizontal resolution leads to the insufficient northward transport of cool water along this coast and an erroneous southward stretching of the ABF. A similar problem arises in the coupled model if the atmospheric component produces alongshore winds that are too weak. Erroneously warm coastal SSTs spread westward through a combination of advection and positive air-sea feedback involving marine stratocumulus clouds. This study thus highlights three aspects to improve to reduce bias in coupled simulations of the tropical Atlantic: 1) large-scale atmospheric pressure fields; 2) the parameterization of stratocumulus clouds; and 3) the processes, including winds and ocean model resolution, that lead to errors in seasonal SST along southwestern Africa. Improvements of the latter require horizontal resolution much finer than the 18 currently used in many climate models. © 2012 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/52357
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Atmospheric and Oceanic Science, University of Maryland, College Park, MD, United States; National Center for Atmospheric Research, Boulder, CO, United States
Recommended Citation:
Grodsky S.A.,Carton J.A.,Nigam S.,et al. Tropical Atlantic Biases in CCSM4[J]. Journal of Climate,2012-01-01,25(11)