辽宁旅顺与山东龙口能见度对比分析

利用2002-2011年渤海海峡两岸辽宁旅顺和山东龙口地面气象站能见度逐时观测资料，采用等级分析法，统计分析两地平均和分级能见度的年、月、日变化特征。结果表明：位于渤海北岸旅顺的年均能见度值高于渤海南岸的龙口，近10 a两地年均能见度均呈下降趋势，龙口年均能见度降低速度高于旅顺；各级能见度的时间百分比旅顺年际变化较大，而龙口相对稳定；一年中两地10月份月均能见度最高，旅顺月均最低能见度出现在7月，龙口出现在6月，两地能见度日变化特征基本一致，呈一波峰一波谷形势。通过分析天气现象及相关气象因子发现，两地出现低能见度（0-1 km）时，风场、温湿场特征均存在明显区域性差异。

Comparison of visibility in Lvshun of Liaoning province and Longkou of Shandong province

Based on the hourly visibility data from 2002 to 2011 in Lvshun of Liaoning province and Longkou of Shandong province, the daily, monthly and annual visibility characteristics were analyzed by a grade analysis meth- od. The results indicate that the annual mean visibility is higher in Lvshtm than in Longkou, and both averages are in decreasing trends in the recent decade, especially in Longkou. The time percentage of annual visibility in the dif- ferent levels changes significantly in Lvshun, while it is stable in Longkou. The maximum visibilities in both loca- tions appear in October, while the minimum value occurs in July in Lvshtm and June in Longkou, respectively. The monthly visibility characters are similar in Lvshun and Longkou, and each has one peak and one valley. Analysis of weather phenomenon and corresponding meteorological elements shows that the regional differences are significant for wind field, temperature and relative humidity field in Lvshun and Longkou when visibility range is from 0 to 1 kin.