DOI: 10.1002/2015MS000615
Scopus记录号: 2-s2.0-84959916512
论文题名: Enhanced MJO and transition to superrotation in warm climates
作者: Carlson H ; , Caballero R
刊名: Journal of Advances in Modeling Earth Systems
ISSN: 19422466
出版年: 2016
卷: 8, 期: 1 起始页码: 304
结束页码: 318
语种: 英语
英文关键词: Budget control
; Climate models
; Damping
; Feedback
; Equatorial waves
; Madden-Julian oscillation
; Meridional gradients
; Moist static energy
; Rising temperatures
; Spontaneous transition
; Superrotation
; Synoptic-scale eddies
; Climatology
; amplitude
; atmospheric modeling
; energy budget
; equatorial wave
; Madden-Julian oscillation
; temperature gradient
; westerly
英文摘要: Using the NCAR CAM3 model in aquaplanet configuration, we perform a suite of simulations spanning a broad range of warm climates. The simulations show a spontaneous transition to superrotation, i.e., westerly winds at upper levels above the equator. The momentum convergence leading to superrotation is driven by eastward-propagating equatorial waves with structure similar to the modern Madden-Julian Oscillation (MJO), whose amplitude increases strongly with temperature. We analyze the moist static energy (MSE) budget of the model's MJO to identify mechanisms leading to its enhanced amplitude. Two such mechanisms are identified: a rapid increase of mean low-level MSE with rising temperature, as found in previous work, and reduced damping of the MJO by synoptic-scale eddies. Both effects imply a reduced gross moist stability and enhanced MJO amplitude. The reduced eddy damping is caused by the transition to superrotation, which allows a greater penetration of extratropical eddies into the equatorial zone; the dominant effect of this greater penetration is to flatten the meridional gradient zonal-mean MSE, which effectively impedes the generation of anomalous MSE divergence by MJO-modulated eddies. This mechanism implies a positive feedback between superrotation and the MJO which may hasten the transition into a strongly superrotating state. © 2016 The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75922
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Department of Meteorology, Stockholm University, Stockholm, Sweden; Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
Recommended Citation:
Carlson H,, Caballero R. Enhanced MJO and transition to superrotation in warm climates[J]. Journal of Advances in Modeling Earth Systems,2016-01-01,8(1)