A two-dimensional land and sea breeze model has been used for the investigation of the circulation over Cheju Island. The model which has different diffusion coefficients for the heat and for the momentum transfer is subdivided into two layers: the surface layer and Ekman layer. A Z^* coordinate system and non-uniform mesh have been applied for the model simulation. From the model simulation, we were able to conclude that low-level wind was much stronger over Cheju city than over Seoguipo city during sea breeze, and vice versa during land breeze. The sea breeze circulation was distinctive over Seoguipo area, and weak land breeze circulation was seen over Cheju area. Meanwhile sea breeze and land breeze circulations over Cheju and Seoguipo area, respectively, were not found in the model simulation.

This work investigates the relationship between the sea breeze circulation and ozone concentrations during cold water events in the southeastern coastal area of the Korean Peninsula, where coastal upwelling frequently occur. This analysis was performed based on the classification of two categories, such as cold water and non-cold water events, over the period of 2000-2009. The low air temperature (0.5℃), low SST (5℃) and the wind direction(southerly) are the features of the cold water events in the Southeastern coastal area. Moreover, ozone concentrations in the cases of the sea breeze circulation and cold water events were significantly lower (below 30 ppb) than those (70∼100 ppb) in the non-clod water events, because of the low air temperature (10∼20℃) and high wind speed (3∼5 m/s) around the southeastern coastal area.

Using three-dimensional non-hydrostatical numerical model with one way double nesting technique, atmospheric circulation in the mountainous coastal region in summer was investigated from August 13 through 15, 1995. During the day, synoptic westerly wind blows over Mt. Mishrung in the west of a coastal city, Sokcho toward the East Sea, while simultaneously, easterly upslope wind combined with both valley wind from plain (coast) toward mountain and sea-breeze from sea toward inland coast blows toward the top of the mountain. Two different directional wind systems confront each other in the mid of eastern slope of the mountain and the upslope wind goes up to the height over 2 km, becoming an easterly return flow in the upper level over the sea and making sea-breeze front with two kinds of sea-breeze circulations of a small one in the coast and a large one in the open sea. Convective boundary layer is developed with a thickness of about 1km over the ground in the upwind side of the mountain in the west and a thickness of thermal internal boundary layer from the coast along the eastern slope of the mountain is only confined to less than 200 m. On the other hand, after sunset, no prohibition of upslope wind generated during the day and downward wind combined with mountain wind from mountain towardplain and land-breeze from land toward under nocturnal radiative cooling of the ground surfaces should intensify westerly downslope wind, resulting in the formation of wind storm. As the wind storm moving down along the eastern slop causes the development of internal gravity waves with hydraulic jump motion in the coast, bounding up toward the upper level of the coastal sea, atmospheric circulation with both onshore and offshore winds like sea-breeze circulation forms in the coastal sea within 70 km until midnight and after that, westerly wind prevails in the coast and open seas.