[A-AS05] [EE] Contributions of local and long-range transport to air pollutants in mega-cities

[AAS05-01] Interannual variations of tropospheric ozone in eastern China: the key role of transport

★招待講演

*Hong Liao¹ (1.School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, China)

キーワード：Tropospheric ozone, Transport, Interannual variations, Eastern China, Process analysis

We quantify the interannual variations (IAVs) of tropospheric O₃ over China for years 1986-2012 by using the global three-dimensional Goddard Earth Observing System chemical transport model (GEOS-Chem). With variations in both meteorological parameters and emissions, simulated seasonal mean surface-layer O₃ concentrations over North China (NC, 110-120°E, 32-42°N), South China (SC, 110-120°E, 22-32°N), and Sichuan Basin (SCB, 102-110°E, 27-33°N) show large IAVs; the deviations from the mean are in the range of -7.0% to +7.5%, -6.0% to +6.0%, and -9.6% to +7.0% over NC, SC, and SCB, respectively. The IAVs in surface-layer O₃ by variations in meteorological fields are simulated to be larger than those by variations in anthropogenic emissions. Process analyses are performed to identify key meteorological parameters that influence the IAVs of O₃. Over NC and SC, transport flux and chemical production are found to be the first and second important processes that drive the IAVs of O₃ throughout the year, with relative contributions of, respectively, 46-52% and 28-34% over NC and 59-63% and 16-21% in SC. Over SCB, transport is the most dominant process that leads to the IAVs of O₃, with high relative contributions of 58-87% throughout the year. Our results have important implications for the effectiveness of short-term air quality control strategies in China.