Abstract: Based on meteorological observation data from Dalian Airport from 2019 to 2023 and ERA5 reanalysis data,we employed synoptic and statistical methods to analyze the characteristics of sea fog meteorological factors along the eastern coast of the Bohai Sea-such as wind direction,weather patterns,and sea-air interactions-and the impact of sea fog formation on the minimum visibility at Dalian Airport.The results indicate that when Dalian Airport is affected by sea fog,the most common occurrence is Yellow Sea fog brought by easterly surface winds.In winter,when westerly winds prevail,advection fog and evaporation fog formed over the Bohai Sea also contribute significantly to foggy conditions at Dalian Airport.Under westerly surface wind conditions,the airport is mainly affected by Bohai Sea fog in winter,influenced by two types of weather patterns.The primary moisture source for most sea fog along the eastern coast of the Bohai Sea is sea surface evaporation,with only a minimal contribution from advective transport.A significant positive correlation exists between the minimum visibility at Dalian Airport and the sea-air temperature difference in the eastern Bohai Sea region,and there is an approximately significant linear relationship with the extreme difference values of net turbulent heat flux.