The Influence of the Andes on Cutoff Lows: A Modeling Study*
The Influence of the Andes on Cutoff Lows: A Modeling Study*
复制标题
安第斯山脉对截止低点的影响：建模研究*
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
H. Fuenzalida
中科院分区：
文献类型：
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作者：
R. Garreaud;H. Fuenzalida
摘要利用WRF模式对2005年3月（南夏末）发生在副热带东南太平洋上空的一个低压系统进行了数值模拟。该事件表现出该地区高气压的典型特征，包括其由西北-东南延伸的温带低压槽形成并随后在南美洲西海岸增强。在发展阶段，气旋环流并没有延伸到对流层下层，在系统及其周围只观测到上层非降水云。当冷空气到达大陆时，沿着安第斯山脉半干旱的西坡[海拔约5000米（ASL）的峰顶高度]产生了温和但非季节性的降雨，同时该系统经历了快速衰减。控制模拟采用全物理、全地形和大气再分析侧向强迫的单一域（54公里网格间距）. ...
Abstract A cutoff low (COL) pressure system that occurred in March 2005 (late austral summer) over the subtropical southeast Pacific is examined by means of numerical simulations using the Weather and Research Forecasting (WRF) model. The episode exhibited typical features of COLs in this region, including its formation from an elongated northwest–southeast extratropical trough and subsequent intensification off the west coast of South America. During the developing stage, the cyclonic circulation did not extend into the lower troposphere and only upper-level, nonprecipitating clouds were observed at and around the system. When the COL reached the continent it produced moderate but unseasonal rainfall along the semiarid western slope of the Andes cordillera [summit level at ∼5000 m above sea level (ASL)] at the same time that the system experienced a rapid decay. The control simulation used full physics, full topography, and a single domain (54-km grid spacing) laterally forced by atmospheric reanalysis. ...