Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Process analysis of typical summertime ozone episodes over the Beijing area
Ist Teil von
The Science of the total environment, 2008-07, Vol.399 (1), p.147-157
Ort / Verlag
Shannon: Elsevier B.V
Erscheinungsjahr
2008
Link zum Volltext
Quelle
Elsevier ScienceDirect Journals Complete
Beschreibungen/Notizen
The 2008 Summer Olympic Games will be held in Beijing; however, summer is the season in which Beijing is marked by frequent high-O
3 episodes. Observation analysis reveals that the urban plume is transported by a southerly wind and undergoes chemical reaction during propagation, resulting in the common occurrence of high O
3 concentrations in the urban downwind area; this is the typical scenario of the formation of high summertime O
3 levels over the Beijing area. The typical high-O
3 episode is well reproduced by the 3-dimensional air-quality model CMAQ-MADRID (Community Multi-scale Air-Quality Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution). Radical cycle analysis reveals that the Beijing urban area was in a VOC-limited regime for O
3 formation, while the urban downwind area changed gradually to a NO
x
-limited condition. The urban downwind area, Dingling, is readily affected by intrusion of the urban plume. Detailed process analysis indicated that although the O
3 peaks reached the same level on 26 and 27 June 2000, the dominant process contributing to the O
3 increase was different on each day. On 26 June, the major contributor to the O
3 peak at Dingling was the arrival of high O
3 levels with propagation of the urban plume; in contrast, on 27 June O
3 precursors were transported rapidly to the urban downwind area by strong transportation processes that occurred earlier than those on the previous day, resulting in O
3 production by local photochemistry becoming the major contributor to the high-O
3 episode.