Document Actions
Variations of O3 and CO in summertime at a rural site near Beijing
Abstract
Atmos. Chem. Phys. Discuss., 8, 10397-10414, 2008
Variations of O3 and CO in summertime at a rural site near Beijing
Y. Wang1,2, M. B. McElroy1, J. W. Munger1, J. Hao2, H. Ma2, C. P. Nielsen3, and Y. Chen2
1Department
of Earth and Planetary Sciences and School of Engineering and Applied
Sciences. Harvard University, Cambridge, Massachusetts, USA
2Department of Environmental Science and Engineering, Tsinghua Univeristy, Beijing, China
3Harvard China Project and School of Engineering and Applied Sciences. Harvard University, Cambridge, Massachusetts, USA
Large intra-season differences in concentrations of CO and O3 ([CO],
[O3]) were detected at Miyun, a rural site north of Beijing, in summer
2006. Despite an increase in mean daytime [CO] from 500 ppbv in June to 700 ppbv in July,
mean daytime [O3] dropped from 67 ppbv in June to 50 ppbv
in July and August. The observed changes in CO and O3 are attributed to
the influence of the summer monsoonal circulation that develops over the
North China Plain in July. Photochemical production of O3 is reduced as
a consequence of increased cloudiness during July and August, as indicated
by the strong negative correlation observed between [O3] and satellite
observations of cloud optical depth, with cloudiness having little effect on
CO. The analysis suggests a strategy for emission controls that could be
implemented in an economically efficient manner to minimize the frequency of
high levels of O3 during summer in Beijing.
Full text of the paper, currently in public peer review phase of ACP, is available at the Atmospheric Chemistry and Physics Discussions website.