This study investigates the temporal and spatial variations of marine meterological elements (air temperature (Temp), Sea Surface Temperature (SST), and Significant Wave Height (SWH)) in seven coastal waters of South Korea, using hourly data observed at marine meteorological buoys (10 sites), Automatic Weather System on lighthouse (lighthouse AWS) (9 sites), and AWS (20 sites) during 2013-2017. We also compared the characteristics of Temp, SST, and air-sea temperature difference (Temp-SST) between sea fog and non-sea-fog events. In general, annual mean values of Temp and SST in most of the coastal waters were highest (especially in the southern part of Jeju Island) in 2016, due to heat waves, and lowest (especially in the middle of the West Sea) in 2013 or 2014. The SWH did not vary significantly by year. Wind patterns varied according to coastal waters, but their yearly variations for each coastal water were similar. The maximum monthly/seasonal mean values of Temp and SST occurred in summer (especially in August), and the minimum values in winter (January for Temp and February for SST). Monthly/seasonal mean SWH was highest in winter (especially in December) and lowest in summer (June), while the monthly/seasonal variations in wind speed over most of the coastal waters (except for the southern part of Jeju Island) were similar to those of SWH. In addition, sea fog during spring and summer was likely to be in the form of advection fog, possibly because of the high Temp and low SST (especially clear SST cooling in the eastern part of South Sea in summer), while autumn sea fog varied between different coastal waters (either advection fog or steam fog). The SST (and Temp-SST) during sea fog events in all coastal waters was lower (and more variable) than during non-sea-fog events, and was up to 5.7℃ for SST (up to 5.8℃ for Temp-SST).

In this study, characteristics of fog at Mokpo as the west coastal area of Jeonnam were investigated, using statistical analysis of observed fog and meteorological data. Higher frequency of the fog occurrence at Mokpo was showed in spring(32%) and summer(34%) due to the seasonal high atmospheric pressure. Regional characteristics as radiation cooling, advection of fog and water vapor from surrounding sea and Yeongsan lake, and frontal fog had major effect on the coastal fog at Mokpo on the meteorological conditions of north-west/south wind and calm(0～2m/s). Also, as the results of analyzing data of before and after the construction of Yeongsan dam, the frequency of annual mean fog days increased 41%, specially increased 178% in autumn. The increase of fog days mainly resulted from evaporation during colder seasons and from temperature inversion during warmer seasons over the water surface of Yeongsan lake. The construction of Yeongsan dam had a little effect on the meteorological conditions concerning fog occurrence, because Yeongsan dam which only supplies the water for use do not always carry out outlet of the cold water. In addition, the sea fog at Heuksando located in offshore had not effect on the occurrence of fog at Mokpo.

하계 한국 남서연안 해역에는 저온수가 나타나고 안개가 자주 형성되는 것으로 알려져 있다. 본 연구에서는 저온수의 출현시기 및 장소와 이 해역에서 형성되는 안개에 미치는 저온수의 영향에 대해 조사·분석하였다. 그 결과, 저수온역은 초여름 대흑산도 부근해역에서 나타나기 시작하여, 이것은 점차 이동하여 7월 말~8월 초 진도 남서쪽 해역에 위치하고, 그 후 10월 중순경 이 해역에서 소멸된다. 그리고 이 해역에서는 주로 4~8월에 안개가 발생하는데, 특히 인근해역에 비해 해면온도가 현저하게 낮은 진도해역에서 안개 발생빈도가 높은 것으로 보아, 이 해역에 나타나는 저온수가 안개의 형성에 상당한 영향을 끼치는 것으로 사료된다.