辽宁沿海高速公路浓雾气候特征及气象影响因子

利用2005—2018年辽宁沿海高速公路沿线气象站点观测资料和NCEP再分析资料，对辽宁沿海高速公路浓雾气候特征及其与各相关气象要素的关系进行分析，并探讨了利于浓雾发生的环流特征和影响因子。结果表明：辽宁沿海高速公路年均浓雾日数由西至东呈现高—低—高的分布特点，同时，辽东沿海高速公路沿线各站年均浓雾日数差异较小，且存在明显的自东向西的下降趋势；辽西沿线高速公路各站差异最大，受到局地的影响最强。沿海高速公路年均浓雾日数具有明显的月变化与季节变化特征，全年有两个浓雾出现的集中时段，分别为2—3月和10—11月；秋季浓雾日数占全年的比率最高。秋季沿海高速公路浓雾以0—200 m的强浓雾为主；温度为10—15℃，相对湿度大于98%，风速为0—3 m·s^-1，风向为偏东北风时，浓雾出现的概率最大。辽宁秋季沿海地区受副热带高压影响较小，受东亚大槽等中高纬度纬向环流和极涡的影响较大，纬向环流和极涡越强（弱），辽宁沿海地区浓雾日数越多（少）；辽宁沿海地区浓雾的水汽一部分来源于辽宁东部山区，一部分来源于渤海、黄海北部。辽宁沿海地区秋季浓雾并非以海雾为主，而以辐射雾、锋面雾居多，同时辽东沿海地区有来自辽东山区的平流雾。

Climate characteristics and meteorological impact factors of heavy fog along Liaoning coast expressway

Observation data from the meteorological stations along Liaoning coastal expressway and the NCEP(National Centers for Environmental Prediction)reanalysis data from 2005 to 2018 were used to analyze the climatic characteristics of heavy fog along Liaoning coastal expressway and its relationship with relevant meteorological elements.The influence factors of circulation on heavy fog were also studied.The results show that the average annual heavy fog days of Liaoning coastal expressway has a high-low-high feature from west to east.The average number of the annual heavy fog days of east and south coast coastal expressway in Liaoning province is the largest.The average number of fog days along the east coastal expressway in the east of Liaoning province has a significant decreasing trend from east to west.The difference of the average number of the annual heavy fog days of each expressway station along the western Liaoning province is the biggest and the local influence on the western coastal expressway is the strongest.The average annual number of heavy fog days in coastal expressway has obvious monthly and seasonal variation characteristics.Heavy fog days occur most frequently in October and less in May.The highest proportion of the number of heavy fog days in the whole year occurs in autumn,and the lowest is in summer.The fogs in autumn are strong mainly appearing at the height from 0-200 m,with the temperature in10-15℃,relative humidity more than 98%,wind speed between 0-3 m·s^-1,and northeastern wind prevailing.Based on the analysis of circulation characteristics,we conclude that the coastal areas in Liaoning province in autumn are less affected by the subtropical high and normally affected by the latitudinal circulation and polar vortex.The stronger or weaker the zonal circulation and polar vortex are,the more or less heavy fog days are in the coastal areas of Liaoning province.The water vapor comes from the eastern mountainous area of Liaoning province,the Bohai Sea,and the northern part of the Yellow Sea.The fog form along Liaoning coast expressway in autumn is not the sea fog,but the frontal and radiation fogs.The advection fog over the east coast of Liaoning province comes from eastern mountainous area of Liaoning province is also another form.