Analysis of Low Cloud and Low Visibility Characteristics and a Frontal Fog Weather in Tongren Airport

本文基于铜仁机场自动观测数据，对影响运行的低云低能见度(能见度低于1000米且云高低于90米)的特征进行统计分析。结果表明：铜仁机场低云低能见度年际变化特征明显。季节变化特征为：冬季 > 春季 > 秋季 > 夏季，主要出现在冬春季节。月变化特征为：全年均可出现，1月出现最多，2月次之，8月出现最少。日变化呈M型分布，峰值均为北京时间06时，均主要出现在03~09时，11~17时均很少出现。低云低能见度持续时间与出现次数大致成反比，主要分布在6 h以内(占71.2%)，在2 h内频率最高，24 h (含)以上频率最低。Based on the automatic observation data of Tongren Airport, this paper makes a statistical analysis of the characteristics of low cloud and low visibility (visibility less than 1000 m and cloud height less than 90 m) affecting operation. The results show that the interannual variation characteristics of low cloud and low visibility in Tongren Airport are obvious. The seasonal variation characteristics are: winter > spring > autumn > summer, mainly in winter and spring. The monthly variation characteristics are as follows: it can appear throughout the year, with the most in January, followed by February, and the least in August. The diurnal variation showed an M-shaped distribution, and the peak values were all at 06:00 am Beijing time, mainly appeared at 03:00~09:00, and rarely appeared at 11:00~17:00. The duration of low cloud and low visibility is roughly inversely proportional to the number of occurrences, mainly distributed within 6 h (accounting for 71.2%), with the highest frequency within 2 h and the lowest frequency above 24 h (including).