基于20年卫星遥感资料的黄海、渤海海雾分布季节特征分析

摘要

Our current knowledge of the sea fog distribution are mostly obtained from the coastal weather stations, ships,and buoys observational data.However these data are limited in spatial distribution,quality control and repr-esentativeness.Thus we are lack of a comprehensive understanding of the distribution of sea fog.Satellite data are known as uniform spacial distribution,wide coverage and relatively consistent quality.Under cloudless conditions, satellite data have the advantages of monitoring large-scale,offshore sea fog.Base on the frequency of fog and cloud together with the percentage distribution,we obtained comprehensive seasonal variation characteristics of the fog in the Yellow Sea and Bohai Sea from 1989 to 2008 .Besides the conclusions confirms those found in the literature, this work also revealed the following facts:(1)The seasonal variation in fog frequency of the Yellow Sea is more significant than that in the Bohai sea.(2)The fog in the Bohai Sea and the Yellow Sea occur more frequently than expected in winter.(3)In the course of sea fog formation and dissipation,there are the phenomena of eastward propagation of sea fog coverage.(4)In the spring and summer fog season,there are two sea fog-prone areas,loca-ted in the middle of Yellow Sea and the West Korea Bay respectively.And the annual maximum fog occurrence is in the West Korea Bay.Furthermore,in the case of sufficient sample population,based on the statistical analysis of the frequency of clouds and sea fog,the datasets generated by the algorithm can be used to estimate the average probability of the fog occurrence in the Yellow Sea and Bohai Sea for the next 20 years.%目前对海上雾分布的认识多基于沿岸测站和海上船舶、浮标观测，但这些数据非常稀少，且存在代表性和数据质量方面的问题，因此一直缺乏对海雾分布更全面、清晰的了解。卫星遥感数据空间均一、覆盖范围广、质量一致，具有对无云条件下大范围、离岸海雾监测的优势。本文通过分析算法检测出的1989－2008年黄渤海海雾及云的频数、分布百分率信息，得到了黄渤海海雾季节变化的较全面特征。除印证其他资料或研究的结论外，还发现：（1）黄海海雾频数随季节变化的幅度较渤海明显；（2）黄海、渤海海域存在冬季海雾多发时段；（3）海雾生消过程中有覆盖区变化的东传特征；（4）春夏雾季中存在黄海中部和西朝鲜湾两处海雾多发区，其中西朝鲜湾也是全年海雾最多的海域。另外，在样本充足的情况下，通过对检测出的低云、中高云覆盖百分率和海雾频数的分析统计，还能估算出黄海、渤海部分季节20年海雾发生的平均概率。