The Role of Momentum Transport in the Motion of a Quasi-Idealized Mesoscale Convective System
The Role of Momentum Transport in the Motion of a Quasi-Idealized Mesoscale Convective System
复制标题
动量输运在准理想化中尺度对流系统运动中的作用
DOI：
10.1175/2009mwr2895.1
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发表时间：
2009
影响因子：
3.2
通讯作者：
M. Parker
中科院分区：
文献类型：
--
作者：
K. Mahoney;G. Lackmann;M. Parker
摘要利用一个模拟的中纬度中尺度对流系统（MCS）研究了动量输送对MCS运动的贡献。动量预算计算使用模式输出，以量化的作用，在确定系统的地面冷池的低层风场的具体过程。结果表明，在MCS前沿对流线附近和冷池前缘附近，扰动风的垂直平流对动量场的影响最大。穿过系统的中后部，风场主要是压力梯度加速度的产物，并且在较小程度上是背景环境的垂直平流（即，基本状态）风。欧拉动量收支中垂直平流项的相对大小表明，对于阵风锋驱动的系统，MCS的向下动量输送是MCS运动和潜在严重地面风的重要驱动因素。结果进一步……
Abstract Momentum transport is examined in a simulated midlatitude mesoscale convective system (MCS) to investigate its contribution to MCS motion. Momentum budgets are computed using model output to quantify the role of specific processes in determining the low-level wind field in the system’s surface-based cold pool. Results show that toward the leading convective line of the MCS and near the leading edge of the cold pool, the momentum field is most strongly determined by the vertical advection of the storm-induced perturbation wind. Across the middle rear of the system, the wind field is largely a product of the pressure gradient acceleration and, to a lesser extent, the vertical advection of the background environmental (i.e., base state) wind. The relative magnitudes of the vertical advection terms in an Eulerian momentum budget suggest that, for gust-front-driven systems, downward momentum transport by the MCS is a significant driver of MCS motion and potentially severe surface winds. Results furthe...