A modeling of the sea breeze and its impacts on ozone distribution in northern Taiwan

A high-resolution air pollution numerical model system (APOPS) is applied to simulate the sea/land breeze and its impacts on the ozone distribution in northern Taiwan. The system can successfully simulate local flow patterns such as sea/land breezes and mountain-valley wind. The predicted surface ozone concentrations also agree with observed surface ozone values (Wang, Z., et al., Tellus, 52B, 2000, 1189). The sea/land breezes in northern Taiwan play a significant role in the distribution of ozone and transport of ozone from the urban to the coastal and mountain areas. The sea breeze is a weak system, extending vertically to a height of less than 1 km with the wind speed less than 4 ms-1. The land breeze can transport the photochemically produced ozone and its precursors over the sea. The accumulated ozone on the sea can return to the land in the daytime with the sea breeze. This kind of transport tends to contribute significantly to high-ozone episodes in clean coastal and mountain regions.