Ozone production and trace gas correlations during the June 2000 MINATROC intensive measurement campaign at Mt. Cimone

[摘要] 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 studyphotochemical ozone production in the lower free troposphere. In general, average mixingratios of important trace gases were not very high (121 ± 20 ppbv CO, 0.284± 0.220 ppbv NOx, 1.15 ± 0.8 ppbv NOy, 58 ± 9 ppbv O₃), which indicates a small contribution by localpollution. Those trace gas levels are representative of continental background air, which isfurther supported by the analysis of VOCs (e.g.: C₂H₆= (905± 200) pptv, C₃H₈= (268 ±110) pptv, C₂H₂= (201± 102) pptv, C₅H₈ = (111 ± 124)pptv,benzene = (65± 33) pptv). Furthermore, significant diurnal variations for a number of trace gases(O₃, CO, NOx, NOy, HCHO) indicate the presence of free tropospheric airmasses at nighttime as a consequence oflocal catabatic winds. Average mid-day peroxy radical concentrations at Mt. Cimone are ofthe order of 30 pptv. At mean NO concentrations of the order of 40 pptv this gives rise tosignificant in situ net O₃ production of 0.1-0.3 ppbv/hr. The importance ofO₃ production is supported by correlations between O₃, CO, NOz, and HCHO, and betweenHCHO, CO andNOy.

[学科分类] 大气科学