2017-11-15安徽颍上团雾天气特征分析及气象服务探讨

团雾是一种严重威胁公路交通安全的恶劣天气,因其具有较强的局地性、突发性特点,也是目前公路交通气象预报服务的难点之一。针对2017年11月15日发生在安徽阜阳滁新高速颍上段的团雾交通事故,利用颍上交通气象站、焦岗湖交通气象站与颍上气象站的逐10 min气温、相对湿度、风速、能见度监测数据,结合欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts)的分析场资料,分析了安徽颍上团雾交通事故发生地的局地环境特征和当日的天气特征及成因,探讨了高速公路团雾预报服务的不足和未来工作展望,为进一步做好团雾天气交通气象服务提供借鉴和参考。主要结论如下:此次团雾发生在辐射雾的天气形势背景下,夜间辐射降温幅度达5℃以上,为团雾发生提供了低温条件;团雾发生地地势低洼且临近水系,水汽输送通道流畅,水汽充足,黎明后底层空气湿度维持在85%以上,是团雾发生的诱因之一;日出后风力保持静风状态,空气流动性差,造成近地面层水汽聚集,是团雾发生的重要原因。

Analysis of Weather Characteristics of the 15 November 2017 Agglomerate Fog in Yingshang of Anhui Province and Rethinking of Meteorological Services

Agglomerate fog is a kind of severe weather which seriously threatens highway traffic safety,for it happens suddenly and locally.It is also one of the difficulties of highway traffic meteorological service.Regarding the fog traffic accident that happened on 15 November 2017 in the Yingshang section of Chuxin highway in Fuyang,Anhui province,this paper analyzes the weather features and causes for the agglomerate fog when the traffic accident took place,and discusses the relationship between the occurrence of agglomerate fog and local environment by using the observations of 10 min temperature,relative humidity,wind speed,visibility collected from the Yingshang and Jiaoganghu automatic weather stations on highway and the Yingshang national weather station,and combing with the analysis data from ECMWF(European Centre for Medium-Range Weather Forecasts).In addition,the deficiency and outlook are summarized through the national and provincial meteorological services,which could provide some references for improving the traffic meteorological service.The results show that the agglomerate fog this time occurred when radiation fog was widespread.The temperature dropped more than 5℃at night as the result of radiation cooling,forming the low temperature conditions for the occurrence of agglomerate fog.The locality where the fog occurred is low-lying and adjacent to the water,the water vapor transport channel is unimpeded and the water vapor is sufficient.The humidity of ground air maintained more than 85%after dawn,which is one of the inducements for the occurrence of the agglomerate fog.More important reason for the agglomerate fog is that the air mobility was poor that day due to the calm condition after sunrise,resulting in the accumulation of water vapor in the near-surface layer.