摘要
利用南宁机场自动观测数据、ERA50.25°×0.25°再分析资料,从环流背景、不稳定层结、水汽条件和冷却条件等方面对2024年1月14日、3月5日和3月30日南宁机场3次辐射雾天气过程进行分析。结果表明,对于辐射雾过程,温度露点差的阶梯式下降、逐小时温度的高下降率、大雾发生期间逐小时温度的持续下降有利于出现能见度的极端低值(200~300 m);较弱的水汽输送条件下,局地的高湿条件(湿层延伸至500 hPa)配合辐射降温及近地层的逆温层仍能促使大雾的发生和维持;正、负速度的转换有利于地表雾区在边界层内混合,进而出现低云;近地层存在较弱但长时间下沉运动时,有利于近低层水汽聚集,容易出现300 m以下的低云且云底高和能见度持续下降,当下沉运动加强且向地面延伸,能见度会出现最低值。
Using automatic observation data from Nanning Airport and ERA50.25°×0.25°reanalysis data,the three radiation fog weather processes at Nanning Airport on January 14,March 5,and March 30,2024 were analyzed from the aspects of circulation background,unstable stratification,water vapor conditions,and cooling conditions.The results show that for the radiation fog process,for the radiation fog process,the stepwise decrease in temperature dew point difference,the high hourly temperature decrease rate,and the continuous hourly temperature decrease during the occurrence of heavy fog are conducive to the occurrence of extreme low visibility values(200 to 300 meters);Under weak water vapor transport conditions,local high humidity conditions(with the wet layer extending to 500 hPa)combined with radiative cooling and a near surface inversion layer can still promote the occurrence and maintenance of heavy fog;The conversion of positive and negative velocities is beneficial for the mixing of surface fog areas within the boundary layer,leading to the appearance of low clouds;When there is weak but long-term sinking motion in the near surface layer,it is conducive to the accumulation of water vapor in the near lower layer,which is prone to low clouds below 300 meters and continuous decrease in cloud base height and visibility.When the sinking motion strengthens and extends to the ground,the visibility will reach its lowest value.
出处
《科技创新与应用》
2025年第1期116-119,123,共5页
Technology Innovation and Application
关键词
辐射雾
温度露点差
水汽条件
风廓线雷达
天气
radiation fog
temperature dew point difference
water vapor
condition wind profile radar
weather
