影响云南地区适航条件的视程障碍天气气候特征

Influence of Visual Obstruction Weather on Airworthiness Conditions and Its Climatic Characteristics in Yunnan

利用云南省1981—2013年125站逐日逐6h地面观测的天气现象、能见度和气象要素资料,结合考虑地形高度的高分辨率气象要素场插值技术和不适航雾(能见度≤800m的大雾天气)气象要素判识模型,开展了影响云南适航条件视程障碍天气的气候特征分析。结果表明:云南最主要的视程障碍天气是雾与轻雾,影响适航条件的视程障碍天气仅为雾。不适航雾生成与相对湿度、风速以及地气温差关系密切,"高湿—弱风—稳定"的气象条件是其形成维持的关键,其量化判识特征为:相对湿度>98%、风速<3m/s、地气温差<3℃。滇西南、滇南、滇东是云南不适航雾的多发区,尤其景东—思茅—版纳、西盟—澜沧、保山—腾冲和罗平等地区。滇中、滇西和滇东北是少发区。云南不适航雾日变化呈现早晨和深夜多,午间和傍晚少的特征;季节变化具有夏秋季多于冬春季的特点。与台站观测相比,高分辨率资料客观判识的不适航雾空间分布与地形有合理的对应关系,能够合理地反映地形复杂地区的空间分布特征。未来技术发展可利用卫星反演资料与台站资料同化订正获取高分辨率气象要素资料,利用深度学习等建立不适航雾的判识模型。

Based on the 6-hour data of weather phenomena,visibility and common meteorological elements from 1981 to 2013 from 125 observation stations over Yunnan,considering the terrain heights,by means of the high resolution meteorological element interpolation method and the objective identification model of meteorological elements for foggy weather unsuitable for flights(the heavy fog with visibility less than 800 m),the influence of visual obstruction weather on airworthiness conditions and its climatic characteristics in Yunnan are analyzed.The results indicate that the primary visual obstruction weather in Yunnan was fog and mist,but the visual obstruction weather affecting airworthiness conditions was fog.Foggy weather unsuitable for flights has a close relationship with relative humidity(RH),wind speed(WS),and the difference of surface temperature and air temperature(T_s-T_a);moreover,the key point of occurrence and maintenance of foggy weather unsuitable for flights is the stable meteorological conditions of high humidity and weak wind,with the quantitative indicators:RH>98%,WS<3 m/s,(T_s-T_a)<3℃.The southern,southwestern and eastern Yunnan Province are the regions where foggy weather unsuitable for flights frequently occurres,especially Jingdong-Simao-Xishuangbanna,Ximeng-Lancang,BaoshanTengchong,Luoping,etc.To compared with the data of observation stations,the spatial distribution of foggy weather unsuitable for flights judged by the high resolution data by the objective method has better correspondence with terrain,which can reasonably reflect the spatial distribution characteristics of complex terrain,while the middle,western and northeastern Yunnan are on the contrary.