Atmospheric Chemistry and Physics Discussions
www.atmos-chem-phys-discuss.net
1680-7367
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2
5
2002
10.5194/acpd-2-1509-2002
http://www.atmos-chem-phys-discuss.net/2/1509/2002/
http://www.atmos-chem-phys-discuss.net/2/1509/2002/acpd-2-1509-2002.html
http://www.atmos-chem-phys-discuss.net/2/1509/2002/acpd-2-1509-2002.pdf
1509
1543
2002-10-07
Ozone production and trace gas correlations during the June 2000 MINATROC intensive measurement campaign at Mt. Cimone
H. Fischer
R. Kormann
T. Klüpfel
Ch. Gurk
R. Königstedt
U. Parchatka
J. Mühle
T. S. Rhee
C. A. M. Brenninkmeijer
P. Bonasoni
A. Stohl
Max Planck Institute for Chemistry, POB 3060, 55020 Mainz, Germany
National Research Council, Institue of Atmospheric Sciences and Climate, via Gobetti 101, 40129 Bologna, Italy
Technical University of Munich, Chair of Bioclimatology and Air Pollution Research, Am Hochanger 13, 85354 Freising-Weihenstephan, Germany
An intensive measurement campaign was performed in June 2000 at the
Mt. Cimone station (44°11' N -- 10°42' E, 2165 m asl, the highest mountain in the northern Italian Apennines) to study
photochemical ozone production in the lower free troposphere. In general, average mixing
ratios of important trace gases were not very high (121 ± 20 ppbv CO, 0.284
± 0.220 ppbv NO<sub>x</sub>, 1.15 ± 0.8 ppbv NO<sub>y</sub>, 58 ± 9 ppbv
O<sub>3</sub>), which indicates a small contribution by local pollution. This is supported by the analysis of volatile organic compounds
(VOCs), that exhibit mean levels typical for background continental air (e.g. 905
± 200\,pptv C<sub>2</sub>H<sub>6</sub> 268 ± 110\,pptv C<sub>3</sub>H<sub>8</sub>, 201
±102 pptv C<sub>2</sub>H<sub>2,</sub> 111 ± 124 pptv isoprene, 65 ± 33
pptv benzene). Furthermore, significant diurnal variations for a number of trace gases
(O<sub>3</sub>, CO, NO<sub>x</sub>, NO<sub>y</sub>, HCHO) indicate the presence of free tropospheric airmasses at nighttime as a consequence of
local catabatic winds. Average mid-day peroxy radical concentrations at
Mt. Cimone are of the order of 30 pptv. At mean NO concentrations of the order of
40 pptv this gives rise to significant in situ net O<sub>3</sub> production of
0.1--0.3 ppbv/hr. The importance of O<sub>3</sub> production is supported by correlations between
O<sub>3</sub>, CO, NO<sub>z</sub>, and HCHO, and between HCHO, CO and NO<sub>y</sub>.