2018年乌鲁木齐机场冻雾导致能见度骤降天气特征分析

Comparative Analysis of the Fog Visibility Plummeting Weather Process at Urumqi Airport in 2018

摘要: 2018年乌鲁木齐机场逐时人工观测能见度数据、再分析资料、自动站、AWOS等资料，分析乌鲁木齐机场2018年因冻雾能见度骤降天气过程的背景条件、温度、湿度条件、RVR变化等，掌握该种天气能见度骤降的表现特点、提出预报着眼点。结果表明：1) 能见度骤降的冻雾天气低能见度持续时间不长，能见度振荡较大，跑道两头RVR相差较大，呈现出团雾或是碎片雾的特征。2) 2011-1-10过程起雾原因是平流雾加辐射雾。东南风对于本场能见度的预报有着重要的指示意义。2018-12-21过程起雾原因为辐射雾。3) 该种天气下，本场冻雾表现为水平方向上分布不均匀且雾层薄。在本场为非东南(南)风的情况下，本场上空的东南(南)风层的高度预示逆温层(或等温层)的高度。

Abstract: Based on the hourly ground observation data, reanalysis data, automatic station and AWOS data of Urumqi Airport, the background conditions, temperature, humidity conditions and RVR changes of the sudden drop of visibility due to frozen fog in 2018 are analyzed, to master this kind of weather visibility in the performance characteristics of a focal point, put forward the forecast. The results show that: 1) In the freezing fog weather when the visibility drops sharply, the duration of low visibility is short, the visibility oscillates greatly, and the RVR difference between the two ends of the runway is large, showing the characteristics of mass fog or debris fog. 2) The reason for fogging in the process of 2018-11-10 is advection fog and radiation fog. Southeasterly wind is very important to forecast local visibility. The cause of fogging in the process of 2018-12-21 was radiation fog. 3) In this kind of weather, the local freezing fog is manifested as uneven distribution in the horizontal direction and thin fog layer. In the case that the local wind is not southeast (south), the height of the southeast (south) wind layer over the field indicates the height of the inversion layer (or isothermal layer).