利用2010-2013年长江江苏段沿线布设的36套自动气象站每分钟1次的能见度、相对湿度、温度、风向和风速等实况监测资料,对江面雾的时空分布特征和气象要素进行了统计分析,结果显示:江面雾主要发生于6、11和1月;主要形成于19时至次日07时,其中02 04时最多,结束于06-12时,持续时间以3～9 h为主.成雾时相对湿度基本在85％以上;主要的温度区间为春季5～19℃、夏季18～26℃、秋季7～23℃、冬季0～11℃;春、夏、秋三季风速都在5 m·s-1以下,冬季风稍大些,甚至在6m·s-1左右的风速下仍然会生成雾,春季以1～2 m·s-1的NNE-E为主;夏季以0.3～1 m· s-1的NNE ESE为主;秋季以0.3～2 m·s-1的NNE-NE和E-ESE为主;冬季以1～2 m·s-1的NNE NE和WNW为主.此外,对出雾时首站的能见度变化进行分析,发现稳定的江面雾形成之前也会形成明显的“象鼻形”先期振荡特征,这一特征给江面雾的预警预报提供了依据.%Using the minutely data including visibility,relative humidity,temperature and wind speed of 36 automatic weather stations along the Yangtze River in Jiangsu Province during 2010-2013,the characteristics of river fogs are analyzed.The results show that river fog mainly occurs in June,November and January,formed from 19:00 BT to the next 07:00 BT,during which the fog is the thickest in 02:00-04:00 BT and gets to end from 06:00 BT to 12:00 BT,so the fog duration is 3-9 h.When fog occurs,relative humidity is 85％ or higher,temperature is 5-19℃ in spring,18-26℃ in summer,7-23℃ in autumn and 0-11℃ in winter.As for the wind speed,it is below 5 m · s 1 in spring,summer,autumn,and about 6 m · s-1 in winter.Specifically,the fog tends to occur with the wind direction of NNE-E and wind speed 1-2 m · s-1 in spring,the wind direction of NNE-ESE and wind speed 0.3-1 m · s-1 in summer,the wind direction of NNE-NE and E-ESE,wind speed 0.3-2 m · s-1 in autumn,and the wind direction of NNE-NE and WNW,wind speed 1-2 m · s-1 in winter.In addition,by analyzing the visibility changes of the first station in the fog,we found that there are obvious "trunk-like" characteristics before river fogs develop.Such features could provide the basis for the operation of early warning and forecasting of river fogs.
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