两次大风过程的对比分析

文章对两次冷空气结合低气压大风过程进行了对比分析,揭示了海上低压轴向的突然向西北转变而引起的地面气压梯度的迅速加大是造成浙北沿海大风的重要原因之一。同时,揭示了两次过程由于高低层辐合辐散差异而引起的大风区上空两类不同的高低空垂直下沉速度分布特征,指出动量下传作用在地面造成风速的加大主要决定于对流层低层下沉速度(而非中层),这可能是两次大风过程地面气压梯度接近,而实际风力却差一级的原因。

The contrasting analysis of strong two wind processes

In this paper two strong wind processes caused by cold air and depression are analyzed.It reveals that the rapidly growing of the surface pressure gradient because of the depression axis suddenly turning toward northwest is one of the important reason which occurs the strong wind along the coast of North Zhejiang Province.Meanwhile,the distribution features of the vertical descending velocity caused by the difference of divergence between the lower lever and the upple lever of two wind processes are pointed out.It indicates that the lower(not the middle) level momentum descending directly strengths the surface wind velocity.This may be the reason of different surface wind velocity of these two wind processes when the surface pressure gradient is nearly same.