Parameterization of the birch pollen diurnal cycle

The purpose of this study was to investigate the patterns of birch pollen counts over a diurnal cycle and propose a parameterization that is useful for inclusion into operational and research short- and long-term modeling for birch pollen atmospheric transport and deposition at different spatial scales. The evaluation of patterns of diurnal cycles on monthly and interannual bases has been done based on analysis of a 26-year time series of birch pollen counts from the Danish pollen measurement site in Copenhagen. The suggested parameterization, based on a simple trigonometric function, includes dependencies on the time of birch pollen maximum and minimum occurrence on a diurnal cycle, averaged concentration at the end of the previous day, and time shift.