Meetstrategieontwikkeling voor het representativiteitsonderzoek als onderdeel van het additioneel meetprogramma ammoniak: fenomenologie van NH3 en meetritsimulaties

Abstract

A programme has been developed for measuring concentrations of ammonia in high emission areas aiming at the validation of the system emission/dispersion/deposition of the transport model TREND (Asman and Van Jaarsveld, 1990). On two locations in the Netherlands (Vredepeel, Ede) the concentration of ammonia will be monitored. To analyse the spatial representativeness of the measurements for a 5 x 5 km2 grid cell additional measurements will be carried out. A measuring strategy has been developed based upon a phenomenological study of the behaviour of ammonia in ambient air and measurement simulations by using existing data. The main results of the phenomenological study show a positive temperature effect for the Elspeet data (high temperature, high concentrations) and also a distinct diurnal pattern with higher concentrations during the day (7 mug/m3) and lower concentrations during the night (3 mug/m3). Monthly average concentrations show small variations for the Elspeet data and higher concentrations during early spring for the Vredepeel data. Peak concentrations (>90- percentile value) show no clear correlation with meteorological conditions. The simulations show a 20% inaccuracy in determining the annual average concentration for each additional location in the 5 x 5 km2 grid cell upon application of the developed measuring strategy.