近70年邵阳雾霾天气气候特征分析及其预报

Climate Characteristics Analysis and Forecast of Fog and Haze over Shaoyang in the Past 70 Years

利用邵阳市1951~2017年10个国家基本站和基准站的常规观测资料和NCEP再分析资料,从历史上出现的雾霾天气中选取300例较为典型的区域性大雾天气过程,从气象要素和天气形势等方面入手,分析了邵阳大雾时空分布特征和变化趋势特征。结果表明:1) 邵阳地区大雾具有时空分布不均的特点,雾日的年际变化波动性大、周期性差;邵阳地区冬半年大雾日数明显偏多,夏半年明显偏少。其中11月最多,7月最少。大雾多数集中在3:00~9:00;85%集中在5:00~7:30,消散时间多出现在8:30以后,冬半年大雾出现早,消散晚,夏半年反之。2) 从气象要素来看,地面和850 hPa风速都很小,风速一般在0~3 m?s?1,并且在地面到850 hPa之间有逆温存在,大雾出现的当天相对湿度较大,前一天多出现降水或多为多云天气;3) 形成大雾的地面天气形势类型分为4种形势,均压场型、冷高压底部型、冷高压后部型、锋面型。在掌握大雾的变化特点、规律以及成因的基础之上,找出了预报大雾的一些预报着眼点。

In this paper, routine observation data of 10 National fundamental stations and basic stand of Shaoyang during 1951-2017, and NCEP reanalysis data are used. Typical 300 cases of regional heavy fog weather process in the historical haze and fog weather are selected, from the meteorological elements and weather conditions and other aspects, the time and spatial distribution characteristics and trends in Shaoyang fog are analyzed. The results showed that: 1) There is the characteristics of time and space uneven distribution of fog in Shaoyang, heavy fog day inter annual variability of volatile, periodic difference;heavy fog days is obvious in winter area, the more the summer half year is significantly less, most of November, July at least. The heaviest fog turned up at 3:00 - 9:00;percent 85 of heavy fog appeared in 5:00 - 7:30, most of fog dissipate after 8:30, winter fog appears early, late to dissipate, summer half year instead;2) From the view of meteorological elements, the ground and 850 hpa wind speed are small and wind speed in 0 - 3 m?s?1, there is thermal inversion layer between the ground to the 850 hpa;the relative humidity is bigger in heavy fog, previous the day of fog there are precipitation or cloudy;3) The formation of the heavy fog weather situation is classified into four kinds of situation on the ground, which is uniform pressure field, cold anticyclone at the bottom, rear of cold anticyclone, front type. Based on change characteristics and regularity of the fog and the causes, forecast key of the fog is sought out.