AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
The Relationship between Fluorescent Particles and Ice Nuclei Measured at Two Contrasting Sites: A Coastal Marine Site (Ucluelet, Canada) and a Semi-urban Location (Saclay, France)
DAVID O'CONNOR, Ryan H. Mason, Meng Si, Jixiao Li, Cédric Chou, Robin Dickie, Allan Bertram, Walfried Lassar, Kyle Pierce, Dominique Baisnee, Roland Sarda-Esteve, J. Alex Huffman, University of Denver, CO
Abstract Number: 517 Working Group: Bioaerosols
Abstract Recently there has been an increasing scientific interest in the evaluation and concentration determination of biological particles (pollen, fungal spores and bacteria) in the atmosphere. Such particles can indirectly affect the environment through their ability to act as ice nucleating particles (INPs), thereby influencing the formation of clouds, their lifetimes and properties such as precipitation potential. However few field studies have been performed to gauge the possible contributions of biological particles to such phenomena.
In this work a wideband integrated biological sensor (WIBS-4a) and a micro-orifice uniform-deposit impactor (MOUDI) were co-located at two sampling locations; one situated in Ucluelet, Canada (rural coastal site) and the other in Saclay, France (semi-urban site). Using the WIBS instrument, fluorescent particles were counted and categorized into classes defined by the channels of fluorescence each particle exhibited. Unique trends in size-resolved diurnal distributions were observed for the seven categories. Particle concentrations from each of the seven WIBS particle categories were compared to corresponding INP concentrations obtained using the MOUDI instrument. The quality of fit between fluorescent particle number and INP number varied significantly depending on the fluorescent particle categories used for the correlation, suggesting that not all fluorescent particle types exhibit the same ice nucleating ability. These data will present the beginning point for discussion regarding what particle types may contribute overall INP loading.