一个黄渤海海雾大气水平能见度算法

为了提高对黄渤海海雾天气海面大气水平能见度（以下简称“能见度”）的数值预报能力，利用黄渤海23个沿岸和岛屿测站2013—2017年雾天的地面观测数据，构建了基于湿度信息的能见度算法（A-F算法），并将之应用于黄渤海海雾的能见度数值预报。结果表明，与常用的根据模式预报的云水含量诊断能见度的SW算法（Stoelinga and Warner，1999）相比，A-F算法表现更优，尤其可以诊断出被SW算法漏报的能见度为1～3 km的轻雾，说明A-F算法对黄渤海海雾天气能见度的数值预报具有一定应用价值。若将来加入浮标与船舶观测数据，可以进一步改进A-F算法能见度公式的具体形式；依据本文构建A-F算法的思路，可以发展适合其他海域的海雾天气能见度诊断公式。

An algorithm of atmospheric horizontal visibility associated with sea fog over the Yellow and Bohai Seas

In order to improve the numerical prediction skills for the atmospheric horizontal visibility (hereinafter referred to as "visibility") over sea surface associated with sea fog over the Yellow and Bohai Seas (the YBS), the A-F algorithm that calculates the visibility using air humidity information is constructed based on the surface observation data in foggy weather from 23 coastal and island stations of the YBS from 2013 to 2017, and then it is applied to numerical prediction of visibility associated with sea fog over the YBS. The results show that the A-F algorithm performs better than the SW algorithm (Stoelinga and Warner, 1999) which is commonly used to diagnose visibility using the model-predicted cloud water content. In particular, the A-F algorithm has the capability to diagnose light sea fog areas with visibility between 1 and 3 km that the SW algorithm always fails to forecast, indicating that the A-F algorithm has application value in the numerical prediction of visibility associated with sea fog over the YBS. The specific form of the visibility equation using the A-F algorithm can be further improved if putting in buoy and ship observations. It is possible to develop appropriate visibility algorithms for other seas according to the idea of constructing the A-F algorithm.