 |
| Titel |
Increasing surface ozone concentrations in the background atmosphere of Southern China, 1994–2007 |
| VerfasserIn |
T. Wang, X. L. Wei, A. J. Ding, C. N. Poon, K. S. Lam, Y. S. Li, L. Y. Chan, M. Anson |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 9, no. 16 ; Nr. 9, no. 16 (2009-08-31), S.6217-6227 |
| Datensatznummer |
250007596
|
| Publikation (Nr.) |
 copernicus.org/acp-9-6217-2009.pdf |
|
|
|
|
|
| Zusammenfassung |
| Tropospheric ozone is of great importance with regard to air quality,
atmospheric chemistry, and climate change. In this paper we report the first
continuous record of surface ozone in the background atmosphere of South
China. The data were obtained from 1994 to 2007 at a coastal site in Hong
Kong, which is strongly influenced by the outflow of Asian continental air
during the winter and the inflow of maritime air from the subtropics in the
summer. Three methods are used to derive the rate of change in ozone. A
linear fit to the 14-year record shows that the ozone concentration
increased by 0.58 ppbv/yr, whereas comparing means in years 1994–2000 and
2001–2007 gives an increase of 0.87 ppbv/yr for a 7-year period. The ozone
changes in air masses from various source regions are also examined. Using
local wind and carbon monoxide (CO) data to filter out local influence, we
find that ozone increased by 0.94 ppbv/yr from 1994–2000 to 2001–2007 in air
masses from Eastern China, with similar changes in the other two
continent-influenced air-mass groups, but no statistically significant
change in the marine air. An examination of the nitrogen dioxide (NO2)
column obtained from GOME and SCIAMACHY reveals an increase in atmospheric
NO2 in China's three fastest developing coastal regions, whereas
NO2 in other parts of Asia decreased during the same period, and no
obvious trend over the main shipping routes in the South China Sea was
indicated. Thus the observed increase in background ozone in Hong Kong is
most likely due to the increased emissions of NO2 (and possibly
volatile organic compounds (VOCs) as well) in the upwind coastal regions of
mainland China. The CO data at Hok Tsui showed less definitive changes
compared to the satellite NO2 column. The increase in background ozone
likely made a strong contribution (81%) to the rate of increase in
"total ozone" at an urban site in Hong Kong, suggesting the need to
consider distant sources when developing long-term strategies to mitigate
local ozone pollution. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|