0000000000131874
AUTHOR
C. Sauvage
Chemical and meteorological influences on the lifetime of NO<sub>3</sub> at a semirural mountain site during "PARADE"
Abstract. Through measurements of NO2, O3, and NO3 during the PARADE campaign (PArticles and RAdicals, Diel observations of mEchanisms of oxidation) in the German Taunus mountains we derive nighttime, steady state lifetimes (τss) of NO3 and N2O5. During some nights, high NO3 (~ 200 pptv) and N2O5 (~ 1 ppbv) mixing ratios are associated with values of τss that exceeded one hour for NO3 and three hours for N2O5 near the ground. Such long boundary layer lifetimes for NO3 and N2O5 are usually only encountered in very clean/unreactive air masses whereas the PARADE measurement site is impacted by both biogenic emissions from the surrounding forest and anthropogenic emissions from the nearby urban…
Study of the Chemical Conversion of Aluminum Alloys by Coupling CFDE and EQCM
The ability of the channel flow double electrode (CFDE) technique and electrochemical quartz crystal microbalance (EQCM) for studying in situ chromate phosphate conversion coating on 5182 aluminum alloys was explored. It was first demonstrated that aqueous Cr(VI) can be analyzed quantitatively with the CFDE technique by reduction into Cr(III) on a graphite electrode. Samples used for EQCM were quartz plated by physical vapor deposition using a 5182 alloy target, allowing thin layers of aluminum alloys with a similar chemical composition to be obtained. EQCM was adapted in order to account for the hydrodynamic conditions in an industrial process, by placing the quartz in a flow cell. In orde…
Chemical and meteorological influences on the lifetime of NO3 at a semi-rural mountain site during PARADE
Through measurements of NO2, O3 and NO3 during the PARADE campaign (PArticles and RAdicals, Diel observations of mEchanisms of oxidation) in the German Taunus mountains we derive nighttime steady-state lifetimes (τss) of NO3 and N2O5. During some nights, high NO3 (∼ 200 pptv) and N2O5 (∼ 1 ppbv) mixing ratios were associated with values of τss that exceeded 1 h for NO3 and 3 h for N2O5 near the ground. Such long boundary-layer lifetimes for NO3 and N2O5 are usually only encountered in very clean/unreactive air masses, whereas the PARADE measurement site is impacted by both biogenic emissions from the surrounding forest and anthropogenic emissions from the nearby urbanised/industrialised cen…