海陆风环流和城市热岛环流相互作用及其对空气污染的影响

Besides emission sources and weather conditions,PM2.5 and ozone in coastal urban areas can be influenced by the sea⁃land breeze circulation and the urban heat island circulation. By using the meteorological and environmental observation data of Hangzhou,2015,and the RBLM⁃Chem model,the features of the pollutants in Land⁃Breeze (LB),Sea⁃Breeze (SB) and Sea⁃Land Breeze (SLB) three different circulation conditions and urban surface and no⁃urban surface two surface conditions are studied. Main conclusions are as following：during sea breeze,the concentrations of PM2.5 and ozone are increased. In statistical results,the maximum increase are 12.0 μg·m-3 and 10.9 μg·m-3 respectively. In simulated results,compared with LB,in SLB the average concentrations are increased by 13.1 μg·m-3 and 18.9 μg·m-3respectively; compared with SB,in SLB the average concentrations are increased by 24.1 μg·m-3 and 11.6 μg·m-3 respectively. Urban effect increases the boundary layer height by 63.8 m,decreases surface wind speed by 0.99m·s-1,increases the surface air temperature by 1.14 ℃ and increases the concentrations of PM2.5 and ozone by 2.86 and 10.2 μg·m-3 respectively. Urban effect is weakened in Hangzhou during sea breeze,its impacts on boundary layer height,surface wind speed,surface temperature and ozone concentration are decreased by 11.2 m,0.49 m·s-1,0.26 ℃ and 7%,respectively.

Keywords： sea breeze effect ; urban effect ; air pollution