Technical Note: Quantification of interferences of wet chemical HONO LOPAP measurements under simulated polar conditions J. Kleffmann and P. Wiesen Physikalische Chemie – Fachbereich C, Bergische Universität Wuppertal, 42097 Wuppertal, Germany
Abstract. In the present pilot study, an optimized LOPAP instrument (LOng Path
Absorption Photometer) for the detection of nitrous acid (HONO) in the
atmosphere (DL 0.2 pptV) was tested at the high alpine research station
Jungfraujoch at 3580 m altitude in the Swiss Alps under conditions
comparable to polar regions. HONO concentrations in the range <0.5–50 pptV
with an average of 7.5 pptV were observed at the Jungfraujoch. The diurnal
profiles obtained exhibited clear maxima at noon and minima with very low
concentration during the night supporting the proposed photochemical
production of HONO. In good agreement with recent measurements at the South
Pole, it was demonstrated, that interferences of chemical HONO instruments
can significantly influence the measurements and lead to considerable
overestimations, especially for low pollution level. Accordingly, the active
correction of interferences is of paramount importance for the determination
of reliable HONO data.
Citation: Kleffmann, J. and Wiesen, P.: Technical Note: Quantification of interferences of wet chemical HONO LOPAP measurements under simulated polar conditions, Atmos. Chem. Phys., 8, 6813-6822, doi:10.5194/acp-8-6813-2008, 2008.