AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
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Sugar Polyol and Bioaerosol Concentration Variations Influenced by Rainy and Dry Periods in a Semi-Arid Rocky Mountain Pine Forest
MARIE GOSSELIN, Chathurika Rathanyake, Ian Crawford, Christopher Pöhlker, Janine Frohlich-Nowoisky, Beatrice Schmer, Guenter Engling, Martin Gallagher, Elizabeth Stone, Ulrich Poeschl, J. Alex Huffman, University of Denver
Abstract Number: 470 Working Group: Bioaerosols
Abstract During the summer of 2011, aerosol sampling was conducted as part of the BEACHON-RoMBAS campaign (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics, and Nitrogen – Rocky Mountain Biogenic Aerosol Study) performed at the Manitou Experiment Forest Observatory located northwest of Colorado Springs, CO. Two instruments utilizing ultraviolet laser-induced fluorescence (UV-LIF) for bioaerosol detection were operated simultaneously with many other instruments, including a high volume filter sampler. Filter fractions were analyzed for sugar polyols including arabitol and mannitol, which are chemical tracers of fungal spores. Another fraction of these filters were analyzed for fungal and bacterial DNA. This study provides the first comparison of UV-LIF instrumentation with more established tracer methods.
The ultraviolet aerodynamic particle sizer (UV-APS) and wideband integrated bioaerosol sensor (WIBS) showed trends that were generally consistent with one another. WIBS data previously analyzed by hierarchical clustering (Crawford et al., Atmos. Meas. Techn., 2015) had assigned a subset of particles to a cluster they defined as fungal spores. We compared the concentrations of different categories of fluorescent particles, including the clusters, with the molecular tracer concentrations and also estimated fungal spore number concentrations from the tracer values. The UV-LIF to molecular tracer correlations varied strongly as a function of meteorological conditions. During and after rain periods the estimated concentration of airborne fungal spores was approx. 3 x 104 m-3 and the concentration of fluorescent particles scaled strongly with both mannitol and arabitol (R2 up to 0.9). During dry periods, fungal concentrations were much lower (approx. 1 x 104 m-3) and the same types of correlations were generally much poorer. Genomic results further suggest that the fungal communities were very different during rainy and dry periods.