Peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN) and PAN/ozone ratio measurements at three sites in Germany

Abstract

PAN and PPN have been measured for some months at a rural site (Lindau) and an urban site (Munich) and during 3 short campaigns at a forest site (National Park Bayerischer Wald) in 1988–1990. PAN was measured concurrently with ozone most of the time, while some concurrent measurements of nitrogen oxides and meteorological parameters have also been made. Monthly mean values of PAN at Lindau were highest during April A strong positive correlation between PAN and O₃ was found during months with high solar radiation, suggesting significant ozone production in the boundary layer at all three sites. The ozone/PAN ratios were lower at higher PAN concentrations at all sites. Influence of wind direction and speed on PAN levels, and dependence on the general weather type are also reported for the Lindau site. These data suggest significant transport from the former East Germany. PPN has also been detected, its concentration in Lindau and Munich being around 11% and 7% of that of PAN, respectively.