静力稳定度对大地形降水影响的数值模拟研究

利用ARPS模式，通过调节过大地形山脉的湿大气静力稳定度进行敏感性试验，研究了湿大气静力稳定度对大地形降水的影响。结果表明，湿大气静力稳定度的改变影响了地形重力波的形成、维持和传播机制。当静力稳定度偏小时，地形重力波容易破碎，得不到有效维持；当静力稳定度偏大时，地形重力波又不易形成；仅当静力稳定度达到适合的强度时，地形重力波才能得到有效维持和传播。此外，垂直上升速度分布、辐合辐散运动及水汽的凝结输送等是影响大地形降水强度及分布状况的重要因素。

NUMERICAL SIMULATION OF THE IMPACT OF STATIC STABILITY ON THE PRECIPITATION INDUCED BY THE HIGH MOUNTAIN

By adjusting the static stability of the moist air current crossing over the high mountain, the APRS model is employed to study the influence of static stability on the precipitation induced by the high mountain. The result shows that the changes of static stability can affect the formation, maintenance and propagation mechanisms of topography gravity wave. The topography gravity wave is easy to break up and can barely maintain duo to the smaller static stability and is not likely to form duo to the larger static stability. Thus, only when the static stability reaches a proper value, the topography gravity wave can maintain and propagate. In addition, the distributions of the vertical ascending velocity, the convergent and divergent motions and the transportation of water vapor are essential influencing factors for the strength and distribution of the precipitation induced by the high mountain.