The Organization of Convection in Narrow Cold-Frontal Rainbands
The Organization of Convection in Narrow Cold-Frontal Rainbands
复制标题
窄冷锋雨带中的对流组织
DOI：
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
G. Moore
中科院分区：
文献类型：
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作者：
G. Moore
摘要 狭窄的冷锋雨带是横跨地表冷锋的强降水线。最近的观测工作表明，该带内的降雨被组织成规则间隔的椭圆体单元，称为降水核心。雨带与强气旋切变线重合，该强气旋切变线与位于地表冷锋前方且平行的低空急流相关。许多作者认为雨带中的单元组织是水平风场剪切不稳定性的结果。为了研究这一假设，对理想化的锋区进行了线性稳定性分析，该理想化的锋区由与气旋切变线重合的对流线组成。为了模拟对流过程，假设雨带内的空气不稳定分层。在不稳定的分层环境中水平风切变的存在导致了短波截止模式的存在。对流介质之间的耦合...
Abstract Narrow cold-frontal rainbands are lines of intense precipitation that straddle surface cold fronts. Recent observational work has revealed that the rainfall within the band is organized into regularly spaced ellipsoidal cells called precipitation cores. The rainband is coincident with a line of intense cyclonic shear associated with a low-level jet that lies ahead of and parallel to the surface cold front. Numerous authors have suggested that the organization of cells in the rainband is the result of shear instability of the horizontal wind field. To investigate this hypothesis, a linear stability analysis was performed on an idealized frontal zone consisting of a line of convection coincident with a line of cyclonic shear. To model the convective processes, the air inside the rainband was assumed to be unstably stratified. The presence of horizontal wind shear in an unstably stratified environment resulted in the existence of a mode with a short wave cutoff. The coupling between the convective p...