2018年春季新乡市一次大风天气诊断分析

Diagnostic Analysis of a Rare Gale in Xinxiang in Spring 2018

本文利用NCEP/NCAR 1°×1°的逐6h再分析数据、气象常规资料,对2018年春季新乡一次罕见的大风天气进行深入分析,研究假相当位温、温度平流、散度、垂直速度等在此次过程中的作用和演变特征。结果表明:700hPa以下较强的冷平流,有利于形成强的地面气压梯度和变压梯度。锋面前侧低空辐合、高空辐散的强烈抽吸作用,促进了华北暖低压的不断发展,从而有利于气压梯度加强:槽前上升、槽后下沉运动,有利于大量扰动有效位能转化为扰动动能,形成斜压不稳定,导致地面出现大风。

Based on NCEP/NCAR 6-hour reanalysis data and routine meteorological data, this paper made an in-depth analysis of a rare gale weather in Xinxiang in spring of 2018, and studied the functions and evolution characteristics of PSEUDO-EQUIVALENT potential temperature, temperature advection, divergence and vertical velocity in this process. The results showed that the strong cold advection below 700hPa was beneficial to the formation of strong surface pressure gradient and pressure gradient. The strong suction effect of low-altitude convergence and high-altitude divergence in front of the front promotes the continuous development of warm and low pressure in North China, which was conducive to the enhancement of pressure gradient. The upward motion in front of the trough and the sinking motion behind the trough were beneficial to the transformation of a large number of disturbance effective potential energy into disturbance kinetic energy, resulting in baroclinic instability and strong wind on the ground.