2019年12月乌鲁木齐机场一次连续两场降雪特征分析

Characteristics Analysis of Two Consecutive Snowfalls at Urumqi Airport in December 2019

摘要: 本文利用乌鲁木齐机场自动气象观测系统观测资料及美国环境预报中心(NCEP)的FNL (Flinal Opera-tional Global Analysis) 0.25 × 0.25再分析资料对2019年12月22~24日机场连续两场降雪天气过程进行研究分析，总结此类天气过程特征，分析机场降雪承载量与除雪时间的关系，为运行决策提供一定参考。结果表明：1) 此次连续降雪的环流背景为中亚低涡稳定少动，多短波活动；2) 逆温层的存在，为强降雪的发生提供了不稳定能量；3) 800~950 hPa存在明显的辐合中心，配合强盛的上升运动及水汽通量散度辐合场，有利于地面出现短时中雪；4) 当乌鲁木齐机场积水厚度达到1.2 mm时，需要短暂关闭机场进行30 min左右的清雪，当积水厚度超过2.2 mm时，若降雪继续维持，则需要长时间关闭机场进行清雪，若降雪不持续时，则跑道经过1小时左右的清雪作业，可以正常使用。

Abstract: This paper uses the observation data of the Urumqi Airport Automatic Weather Observation Sys-tem and the FNL (Flinal Operational Global Analysis) 0.25 × 0.25 reanalysis data of the National Center for Environmental Prediction (NCEP) to study the two consecutive snow weather processes at the airport on December 22~24, 2019, analyze and summarize the characteristics of such weather processes, analyze the relationship between the airport’s snow carrying capacity and snow removal time, and provide a certain reference for operational decision-making. The results show that: 1) the circulation background of the continuous snowfall is the stable low-motion vortex in Central Asia, and more shortwave activities; 2) the existence of the inversion layer provides unstable energy for the occurrence of strong snow; 3) there is an obvious convergence center at 800~950 hPa. Combined with the strong upward movement and the divergence convergence field of water vapor flux, it is conducive to the occurrence of short-term moderate snow on the ground; 4) when the thickness of water in Urumqi Airport reaches 1.2 mm, the airport needs to be temporarily closed for snow removal for about 30 min; when the thickness of water exceeds 2.2 mm, if the snowfall continues, the airport needs to be closed for snow removal for a long time; if the snowfall does not last, the runway can be used normally after about an hour of snow removal.