Abstract
A global 3-D CTM model (OsloCTM2) has been used to study the tropospheric ozone distribution and budget over China. An area covering China and most of East Asia is chosen as the study area. Because of the very unevenly distributed emissions and population in China, the budget study has been done by splitting China into three sub-areas, according to the emission distribution and topography of the country. The model results indicate that in Western China (Area1) dynamic processes are dominating, and the contribution from photochemical ozone production is small. Central and South-East China (Area2) has on average 65% of the photochemical ozone production in China, since more than 80% of the anthropogenic emissions come from this area. Northeast China (Area3) is influenced both by natural and*9nthropogenic emissions. The seasonal variation of ozone budgets was calculated in order to understand how different processes vary with the seasons. The strongest influences of emissions from the continent over the West Pacific region are found in spring, because of the large eastward transport and increased photochemical activities. Most NO(subscript x) is consumed close to the emission sources; therefore, only 4% of emitted NO(subscript x) is transported out of China, whereas 70% of the emitted CO is exported. It is calculated that the average net chemical ozone production efficiency by NO(subscript x) loss is 7.2 in China.
Highlights
A number of model studies and ground-based measurements show a notable increase of surface ozone in the Northern Hemisphere since pre-industrial times
It is more suitable to use the monthly average results than to use daily or hourly results to compare with measurements, so the analysis of model results and measurements are all based on monthly averages
The comparison between model results and measurements shows that the model has the capability to give reasonable ozone distribution and levels close to the surface
Summary
A number of model studies and ground-based measurements show a notable increase of surface ozone in the Northern Hemisphere since pre-industrial times. During the late 19th century surface ozone mixing ratios were approximately 10 ppbv over Europe (Anfossi et al 1991; Marenco et al 1994). This mixing ratio has increased around four times to 30 - 50 ppbv as typical values over industrial areas (Pavelin et al 1999). These increases are mainly driven by the increases in ozone precursors like NOx (NO + NO2), CO, and NMHC (non-methane hydrocarbons) emitted from anthropogenic fossil fuel combustion and biomass burning. Future emissions are expected to increase in developing countries, especially in South and Southeast Asia (van Aardenne et al 1999; Streets et al 2000; Chinese NEPA 2004)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
