A thermally driven wind system influencing concentrations of ozone precursors and photo-oxidants at a receptor site in the Alpine foothills [Einfluß eines thermisch erzeugten Windsystems auf Konzentrationen von Ozon-Vorläuferschadstoffen und Photooxidantien in einem Voralpental
oleh: A. S. H. Prévôt, J. Staehelin, H. Richner, Th. Griesser
| Format: | Article |
|---|---|
| Diterbitkan: | Borntraeger 1993-09-01 |
Deskripsi
From June to August 1991, a regional network of surface stations was operated in a topographically complex pre-Alpine valley for measuring ozone precursors and photo-oxidants on the valley floor and on one of the slopes. On sunny days with low pressure gradients, thermally generated valley and slope winds prevailed and inversions were formed during the night. Dry deposition and emissions of primary pollutants reduced the concentrations of the photo-oxidants during nighttime. Negative correlations between nitrogen dioxide and ozone were observed in the morning. Results suggest, that the observed strong increase of H2O2 during the afternoon is mainly caused by an air mass change.