On the sizes and lifetimes of cold pools
On the sizes and lifetimes of cold pools
复制标题
关于冷池的大小和寿命
DOI：
10.1002/qj.2754
复制
发表时间：
2015
影响因子：
8.9
通讯作者：
N. Jeevanjee
中科院分区：
文献类型：
--
作者：
D. Romps;N. Jeevanjee
由蒸发降水形成的冷空气池在触发新的降水中起着关键作用。尽管它们的重要性得到公认，但很少有人致力于建立简单的动态模型。在这里，解析方程推导出的半径，高度和浮力的圆柱形冷池作为时间的函数，和尺度分析表明，夹带是一个占主导地位的影响。这些控制方程产生简单的表达式的最大尺寸和寿命的冷池。冷池的终端半径对其初始条件相对不敏感，典型的最大半径约为初始半径的14倍，给定或取2倍。另一方面，冷池的终止时间可以根据其初始势能和动能而在数量级上变化。这些预测是针对大涡模拟验证。
Cold pools of air, which are formed by evaporating precipitation, play a critical role in the triggering of new precipitation. Despite their recognized importance, little effort has been devoted to building simple models of their dynamics. Here, analytical equations are derived for the radius, height, and buoyancy of a cylindrical cold pool as a function of time, and a scale analysis reveals that entrainment is a dominant influence. These governing equations yield simple expressions for the maximum sizes and lifetimes of cold pools. The terminal radius of a cold pool is relatively insensitive to its initial conditions, with a typical maximum radius of about 14 times the initial radius, give or take a factor of 2. The terminal time of a cold pool, on the other hand, can vary over orders of magnitude depending on its initial potential and kinetic energies. These predictions are validated against large‐eddy simulations.