微波辐射计在乌鲁木齐机场浓雾监测中的应用

Application of Microwave Radiometer in Dense Fog Monitoring at Urumqi Airport

选取2016—2017年乌鲁木齐机场冬季浓雾个例,根据浓雾出现时环流形势分为槽后—脊前和偏西气流弱短波两类,进一步分析微波辐射计监测气象要素变化,结果表明浓雾出现、持续、结束与气象要素变化紧密相关:90%浓雾个例出现在综合水汽含量持续下降阶段,浓雾出现前1 h综合水汽含量降幅0.1~1.5 kg/m2。浓雾出现前1 h近地面相对湿度增幅5%~15%,浓雾出现时近地面空气相对湿度出现90%以上的湿区,多数出现相对湿度为95%以上的湿区,并向垂直方向扩展、接地;近地面相对湿度为95%以上的湿区消失,主导能见度好转。浓雾出现前30~60 min近地面探空气温持续降温,同时出现贴地逆温层,500~1500 m高度探空气温增温出现更早;浓雾结束前形成脱地逆温层,近地面出现等温层或减温层;浓雾结束时近地面增温,或近地面等温层或减温层高度达到300 m以上。

In this paper, dense fog cases were selected from 2016 to 2017 in winter at Urumqi Airport. According to circulation situation, dense fog cases were divided into two types： the rear of trough and front of ridge, the west airflow and weak short wave. Further analysis of the change of meteorological elements monitoed by microwave radiometer, showed that dense fog cases occurrence, persistence and ending is closely related to the change of meteorological elements： 90% dense fog cases appear in decline of comprehensive water vapor, and comprehensive water vapor decreases 0.1- 1.5 kg/m2 and relative humidity near ground increases 5%-15% by 1 h before dense fog appearance. When dense fog come, more than 90% wet area appears near ground, more than 95% wet area extends to vertical direction, more than 95% wet area disappears and visibility turns better. By 30-60 min before dense fog appearance, continuous decreasing temperature near ground and ground inversion appears, increasing temperature of 500-1500 m is earlier. Ground inversion layer is lifted before the end of dense fog, isothermal layer or temperature reduction layer appears near ground. At the end of dense fog, temperature near ground increases, or isothermal layer or temperature reduction layer reaches more than 300 m.