Space-borne and ground observations of the characteristics of CO pollution in Beijing, 2000–2010

Both the long-term and short-term variability of carbon monoxide (CO) pollution in Beijing metropolitan area, China are studied with 11 years of MOPITT observations and 10 years of ground measurements. The impact of the 2008 Beijing Olympic Games on regional air quality is also examined. MOPITT CO columns exhibit different temporal patterns from ground CO concentration measurements. MOPITT CO column in August has gradually increased from 2000 to 2007, even though ground level CO concentrations have significantly decreased due to continued local air pollution control effort. Both CO columns and ground CO concentrations were reduced due to strict albeit temporary emissions control measures from July to September 2008 to support the Beijing Olympic Games. However, the reduction of total CO columns (∼13%) was less pronounced than ground CO concentration (∼44%), indicating that local emission control effort was partially offset by the continuously deteriorating regional air quality. In addition, MOPITT CO mixing ratio profiles indicate a significant regional pattern at higher altitudes. CO total columns after 2008 show an overall increasing trend, in contrast to the decreasing trend observed in ground measurements.

► MOPITT CO column seasonal pattern differs from ground CO concentrations in Beijing.
► MOPITT CO column in August has increased from 2000 to 2007, even though ground CO concentrations have significantly decreased in Beijing.
► Emission control measures caused 44% reduction in ground CO concentrations and 13% reduction in CO column during the Beijing 2008 Olympic Games.
► CO total columns show an overall increasing trend, in contrast to the decreasing trend in ground observations.