Copenhagen – a significant source of birch (Betula) pollen?

Abstract

Current aerobiological research applies the hypothesis that the main source of atmospheric birch (Betula) pollen is forest trees. Our results indicate that the measured levels in Copenhagen are not only due to birch trees in Danish forests but that the urban areas also seem to be a significant source of birch pollen. A number of episodes in 2003 with enhanced pollen levels in Copenhagen seem to be associated with parks and gardens inside and just outside the city. Our results also indicate one long-range transport episode from remote sources in Poland and Germany. Finally, our results show that the pollen levels vary considerably over the day and geographically between Copenhagen and the city of Roskilde, 40 km away. We suggest, that these differences in time and space in the pollen levels are mapped using an integrated monitoring strategy.

Crop harvest in Denmark and Central Europe contributes to the local load of airborne <i>Alternaria</i> spore concentrations in Copenhagen

“…1). If the main source of Alternaria spores were remote sources, then this daily pattern could have been either nonexistent or peaked at any time of the day, as the big plumes of LDT of aeroallergens can arrive in Copenhagen at any time of the day or night (Mahura et al, 2007;Skjøth et al, 2007Skjøth et al, , 2008. The number of high days are outnumbered by low days (Table 1), but every year the total load during the season has been dominated by the high days, which contributed up to 82 % of the entire Alternaria load during the season (Table 1).…”

“…Hernandez-Ceballos et al, 2011a). Air mass trajectories were plotted 48 h back in time with 2 h steps between each trajectory, corresponding to the time step of the fungal spore observations -following the method described by Stach et al (2007) and later used by Skjøth et al (2008Skjøth et al ( , 2009, Smith et al (2008), Sikoparija et al (2009), andHernandez-Ceballos et al (2011a, b) -by using either the ACDEP (Skjøth et al, 2002) in the matrix style or the HYSPLIT (Draxler et al, 2007) models. Measured precipitation from weather and climate stations have been used as an estimate for potential Alternaria spore release due to harvest in the potential source regions (Fig.…”

“…Local meteorological observations of wind speeds during the episodes (Table A3) have been obtained from one meteorological mast located approx. 1500 m south of the pollen trap (Skjøth et al, 2008), which is operated by Aarhus University for use in the socalled integrated monitoring of air quality in Denmark (Hertel et al, 2007).…”

“…The sum of low days and high days correspond to the total accumulated catch during the season (the days that cover 95 % of the entire catch) and not the entire year. Skjøth et al (2008). Summaries of the data for the 10 years are organised in two tables in a similar way as Kasperzyk et al (2011) with respect to the annual spore index (the summation of daily mean values), day with maximum concentration and start of season (Table 1).…”

MACC regional multi-model ensemble simulations of birch pollen dispersion in Europe

“…Starting from the 1990s, episodes of pollen dispersion on regional and continental scales have been addressed in numerous studies (Belmonte et al, 2000;Corden et al, 2002;Damialis and Gioulekas, 2005;Hjelmroos, 1992;Latalova et al, 2002;Mahura et al, 2007;Ranta and Satri, 2007;Ranta et al, 2011;Rantio-Lehtimaki, 1994;Siljamo et al, 2008c;Skjøth et al, 2008;Sofiev et al, 2012bSofiev et al, , 2006aYliPanula et al, 2009; see also reviews by Smith et al, 2014, andBergmann, 2013). It was shown that, although the features of each specific long-range transport episode vary widely, there may be a systematic pattern in the springtime pollen redistribution in Europe with prevailing transport directions, main source and receptor regions, etc.…”