Decoding Tropospheric Ozone in Hangzhou, China: from Precursors to Sources

For the purpose of providing a tropospheric O(3)control strategy for Hangzhou, China, we investigate the influential factors of it using observed data and the WRF-CMAQ model. The result indicates that temperature and relative humidity are the dominant factors and Hangzhou belongs to VOC-limited regime. Long-range/regional transport accounts for 15.4% and 17.4% of O(3)in autumn and winter, respectively, showing a north-to-south transport pattern while 14.5% and 19.7% of O(3)in spring and summer, respectively, showing a southwest-to-northeast transport pattern. Annual contribution of local industry to local O(3)was 59.2%, followed by residence, traffic and agriculture. Ethylene, m/p-xylene, toluene and propylene are the main O(3)producers. Therefore, controlling VOCs species that possess the highest ozone formation potentials, afforestation, implementing artificial precipitation and shutdown local industry are the most effective ways to mitigate ozone pollution in Hangzhou.