摘要
本文选取了2017年~2020年乌鲁木齐机场出现的冻降水天气,发现乌鲁木齐机场的冻降水有冻雨和冻毛毛雨,其中以冻毛毛雨天气为主,冻毛毛雨都出现在西北气流控制的天气形势下。同时分析了微波辐射计在冻降水天气时的监测资料,结果表明当冻降水天气出现时,700 hPa以下的相对湿度都有所增加,低层相对湿度甚至达到了95%以上,达到高饱和状态;乌鲁木齐机场的冻降水主要为暖雨机制,整层温度几乎都小于0℃,且分为弱减温层和弱逆温层两种温度结构,但是温差不大,近乎等温;冻降水出现时气温基本维持在−5℃~−7℃,1000米以下的温度维持在−10℃以内;由于乌鲁木齐机场冻降水以冻毛毛雨为主且持续时间短,所以综合水汽含量变化不大,液态水含量略有波动但不明显,液态水廓线呈现出两种形态,但是与冻降水没有很好的对应,考虑冻降水主要是空气中的过冷却水汽达到饱和凝结而成。
This paper selects the frozen precipitation weather of Urumqi airport from 2017 to 2020, and finds that the frozen precipitation of Urumqi airport includes frozen rain and frozen drizzle, of which the frozen drizzle weather is the main one, and the frozen drizzle occurs under the weather situation of Northwest air flow control. At the same time, the monitoring data of microwave radiometer on frozen precipitation weather are analyzed. The results show that frozen precipitation weather occurs, the relative humidity increases below 700 hPa, and the low-level relative humidity even reaches more than 95%, reaching a high saturation state. The frozen precipitation of Urumqi airport is mainly warm rain mechanism. The temperature of the whole layer is almost less than 0˚C, and it is divided into two temperature structures: weak desuperheating layer and weak inversion layer, but the temperature difference is small and almost isothermal. When frozen precipitation occurs, the temperature is basically maintained at −5˚C~−7˚C, and the temperature below 1000 m is maintained within −10˚C. As the frozen precipitation of Urumqi airport is mainly frozen drizzle and lasts for a short time, the comprehensive water vapor content changes little, and the liquid water content fluctuates slightly but not significantly. The liquid water profile presents two forms, which do not correspond well to the frozen precipitation. It is considered that the frozen precipitation is mainly formed by saturated condensation of supercooled water vapor in the air.
出处
《气候变化研究快报》
2021年第6期689-698,共10页
Climate Change Research Letters
