Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 15, 6127-6146, 2015
© Author(s) 2015. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
04 Jun 2015
Regional-scale simulations of fungal spore aerosols using an emission parameterization adapted to local measurements of fluorescent biological aerosol particles
M. Hummel1,*, C. Hoose1, M. Gallagher2, D. A. Healy3, J. A. Huffman4, D. O'Connor3, U. Pöschl5, C. Pöhlker5, N. H. Robinson6, M. Schnaiter1, J. R. Sodeau3, M. Stengel7, E. Toprak1, and H. Vogel1 1Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany
2The Centre for Atmospheric Sciences, The University of Manchester, Manchester, United Kingdom
3Centre for Research into Atmospheric Chemistry, Department of Chemistry, University College Cork, Cork, Ireland
4Department of Chemistry & Biochemistry, University of Denver, Denver, Colorado, USA
5Biogeochemistry Department and Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
6Met Office, Exeter, United Kingdom
7Deutscher Wetterdienst (DWD), Offenbach, Germany
*now at: Department of Geosciences, University of Oslo, Oslo, Norway
Abstract. Fungal spores as a prominent type of primary biological aerosol particles (PBAP) have been incorporated into the COSMO-ART (Consortium for Small-scale Modelling-Aerosols and Reactive Trace gases) regional atmospheric model. Two literature-based emission rates for fungal spores derived from fungal spore colony counts and chemical tracer measurements were used as a parameterization baseline for this study. A third, new emission parameterization for fluorescent biological aerosol particles (FBAP) was adapted to field measurements from four locations across Europe. FBAP concentrations can be regarded as a lower estimate of total PBAP concentrations. Size distributions of FBAP often show a distinct mode at approx. 3 μm, corresponding to a diameter range characteristic for many fungal spores. Previous studies for several locations have suggested that FBAP are in many cases dominated by fungal spores. Thus, we suggest that simulated FBAP and fungal spore concentrations obtained from the three different emission parameterizations can be compared to FBAP measurements. The comparison reveals that simulated fungal spore concentrations based on literature emission parameterizations are lower than measured FBAP concentrations. In agreement with the measurements, the model results show a diurnal cycle in simulated fungal spore concentrations, which may develop partially as a consequence of a varying boundary layer height between day and night. Temperature and specific humidity, together with leaf area index (LAI), were chosen to drive the new emission parameterization which is fitted to the FBAP observations. The new parameterization results in similar root mean square errors (RMSEs) and correlation coefficients compared to the FBAP observations as the previously existing fungal spore emission parameterizations, with some improvements in the bias. Using the new emission parameterization on a model domain covering western Europe, FBAP in the lowest model layer comprise a fraction of 15% of the total aerosol mass over land and reach average number concentrations of 26 L−1. The results confirm that fungal spores and biological particles may account for a major fraction of supermicron aerosol particle number and mass concentration over vegetated continental regions and should thus be explicitly considered in air quality and climate studies.

Citation: Hummel, M., Hoose, C., Gallagher, M., Healy, D. A., Huffman, J. A., O'Connor, D., Pöschl, U., Pöhlker, C., Robinson, N. H., Schnaiter, M., Sodeau, J. R., Stengel, M., Toprak, E., and Vogel, H.: Regional-scale simulations of fungal spore aerosols using an emission parameterization adapted to local measurements of fluorescent biological aerosol particles, Atmos. Chem. Phys., 15, 6127-6146, doi:10.5194/acp-15-6127-2015, 2015.
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