The Simulation Study Of Troposphere Ozone In East Asia Using The Global Atmosphere Chemical Model

This study used global atmospheric chemical transport model MOZART-4to research the seasonal and interannual variability of O3over East Asian and global of O3and the effect of different emission sources on O3. The evaluation of the model shows that the value of simulating C3、CO and CH4over East Asia matched the value of observation. The correlation coefficient at low latitude sites was0.93, while the correlation coefficient at high latitude sites was lowest,0.56. The simulation of volume O3matched well the observation of TOMS. Because of the uncertainty of tropopause, the simulation had small deviation. The contrast of climatologically seasonal aerosol optical depth (AOD) between the simulation and the observation showed that the simulation reproduced the high value of the observation of TOMS over East Asia. The deviation resulted from the low resolution of the emission and model and the special terrain in some areas.The analysis of the seasonal variation of O3pointed out that, the O3seasonal changes in marine monsoon region is mainly affected by the role of stratospheric input; The spring high value of O3in the coastal monsoon region is leaded by strong net photochemical production and stratospheric input, and the contribution of the photochemical reactions to O3is above the stratosphere input, while the summer minimum of O3mainly due to strong convective transport, weak stratospheric input and strong dry deposition, and the sub-peak in fall dues to the net photochemical production; The seasonal variation of O3in the high pollution emission area is caused by photochemical reactions; The O3concentration in winter in Tibetan Plateau is significantly affected by the stratosphere input, while O3in the rest of the seasons is significantly affected by advection and convection; The O3concentration in winter in Waliguan is significantly affected by the stratosphere input, while O3in June is significantly affected by advection; The O3concentration in winter in the non-monsoon region is significantly affected by the stratosphere input, while O3in the rest of the seasons is significantly affected by photochemical reactions and convection. The strength of the monsoon period has a significant impact on inter-annual variation of the surface O3.The susceptibility tests of emission sources reveal that the increase of surface03are closely linked to the primary pollutant emissions (NO and CO) from human activities in Asia since1850, and the NO generated by Lightning mainly occurs in the middle and upper troposphere. The effect of lightning on surface O3is small, while the maximum effect on O3is at the height of the300hPa and the meridional average O3maximum value is at95°E. The global delivery mechanisms of O3in different seasons are variable in North America, Europe and Asia cases. By the equatorial flow toward the South in the middle and upper troposphere over East Asian, the increase of O3in the southern hemisphere is in the middle and upper troposphere, while the increase of surface O3is small. The contribution to tropospheric O3in the southern hemisphere in Asia case is larger than in North America and Europe cases.