The slopes of cumulus clouds in relation to external wind shear
The slopes of cumulus clouds in relation to external wind shear
复制标题
积云的斜率与外部风切变的关系
DOI：
--
复制
发表时间：
1952
期刊：
影响因子：
--
通讯作者：
J. Malkus
中科院分区：
文献类型：
--
作者：
J. Malkus
推导了积云的斜率方程。它取决于垂直上升速率、外部风切变和云与周围环境之间的水平摩擦力。这些摩擦力有两个来源：一个是由于夹带或与外界空气混合，另一个是由于形状或身体阻力。
An equation for the slope of cumulus clouds is derived. It is shown to depend upon the vertical ascent rate, the external wind shear and the horizontal frictional forces between the cloud and its surroundings. These frictional forces are of two origins: one due to entrainment or mixing with the outside air, and the other due to form or body drag.
Four observational cases are presented, one concerning trade cumulus, and three involving clouds in mid-latitudes. In two of these, measurement of updraught speed, wind shear, and cloud slope permit an estimate of the magnitude of the friction forces. The minimum contribution due to entrainment is approximately equal to that inferred by Stommel for trade cumulus.