Update of background concentrations over Norway.

Abstract

A methodology for creating a new dataset of estimated background concentrations of NO2, O3, PM10, and PM2.5 that are representative of a typical year over Norway, was developed. The dataset has a spatial resolution of 10 km × 10 km and an hourly temporal resolution. The methodology is based on a spatial mapping component for obtaining information on annual mean background concentrations, and a temporal characterization component, which uses long-term time series of station data to describe the typical development of background concentrations throughout a day and a year. When combined, these two components allow estimates of typical background concentrations at any time of the year at any location in Norway. Whereas the previously used VLUFT method of 1993 only provided spatially constant data at the county level, the new method presented here provides spatially continuous data at a comparatively high spatial resolution. Furthermore, while the previous method only gave a range of constant values that were considered valid throughout the entire year, the new technique provides continuous time series for a typical year at hourly resolution at any location in Norway.