@article{148291, author = {Denise L. Mauzerall and D. Narita and H. Akimoto and L. Horowitz and S. Walters and D. Hauglustaine and B. Brasseur}, title = {Seasonal Characteristics of Tropospheric Ozone Production and Mixing Ratios Over East Asia: A Global Three-dimensional Chemical Transport Model Analysis}, abstract = { We examine seasonal and geographical distributions of tropospheric ozone production and mixing ratios over East Asia with a global three-dimensional chemical transport model called Model of Ozone and Related Tracers, version 1 (MOZART-1). Net ozone production within the East Asian boundary layer exhibits three distinct seasonal cycles depending on region (north of 20N, 5-20N and south of 5N). North of 20N, net ozone production over East Asia from spring through autumn is found to have a maximum extending from 25N-40N and from central eastern China to Japan, resulting from the strong emission and transport of anthropogenic O3~precursors. In winter, maximum O3~production in this region occurs between 20N and 30N. This is a region of long-range transport. Over the Indochina peninsula, between 5N and 20N, net O3~production is controlled by the seasonal cycle between wet and dry seasons and has a maximum at the end of the dry season due to emissions from biomass burning. South of 5N, in the true tropics, O3~mixing ratios are relatively constant throughout the year and do not exhibit a seasonal cycle. A spring-summer maximum of net O3~production is found throughout the troposphere in East Asia. We estimate an annual net O3~production in East Asia of 117 Tg/yr. Both model results and analysis of measurements of O3-CO correlations over East Asia and Japan show strong variability as a function of both photochemical activity and seasonal meteorology, and indicate ozone export off the coast of East Asia in spring. An upper estimate of O3~export from East Asia to the Pacific Ocean in the mid-1980s of 3.3 Gmol/day (58 Tg/yr) is obtained. }, year = {2000}, journal = {Journal of Geophysical Research}, volume = {105}, pages = {17895-17910}, language = {eng}, }