Using automatic observation data from Nanning Airport and ERA5 0.25°×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 circu-lation 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 de-crease 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 sur-face fog areas within the boundary layer,leading to the appearance of low clouds;When there is weak but long-term sinking mo-tion 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 ex-tends to the ground,the visibility will reach its lowest value.
radiation fogtemperature dew point differencewater vaporcondition wind profile radarweather
万方数据
维普
