This paper uses shipborne observation data,FNL reanalysis data and Sunflower-8 cloud map data to study a persistent strong dense fog process that occurred at the mouth of the Yangtze River estuary from March 11 to 14,2022,and to summarize the practical methods for fog forecasting.The conclusions are as follows:This dense fog process includes radiation fog and frontal advection fog,which has a long duration and a wide range of influence.The fog area appears in the front and rear parts,and the front movement affects the movement of fog.During the lifetime of the dense fog,air temperature and relative humidity are usually negatively correlated,air temperature-dew point difference is positively correlated with the visibility.When air temperature-dew point difference is greater than 3℃,fog also occurs at the mouth of the Yangtze River estuary but the visibility is normally not less than 3 km.The prevailing wind during the dense fog process is usually southerly and northerly.The westerly and northwesterly winds cause the rapid drop of relative humidity,resisting the formation and maintenance of the fog.The visible light cloud map has obvious characteristics of the fog including uniform color texture,clear and neat boundaries,no filamentous or fibrous cloud diffusion on the periphery,while the characteristics of the fog on the infrared cloud map is a gray dark area,only the boundary is faintly visible.
关键词
浓雾/长江口雾/生消过程/水汽输送/预报
Key words
dense fog/fog at the mouth of the Yangtze River estuary/fog lifetime/water vapor transport/forecasting
维普
万方数据