Measurements of Ice Nuclei at a Remote Coastal Site in Western Canada
Wednesday, 17 December 2014
Aerosol particles are abundant in the atmosphere, and they can influence climate by modifying the formation of ice clouds and mixed-phase clouds. Understanding the sources of ice nuclei (IN) should lead to better predictions of climate. Many current instruments for measuring atmospheric concentrations of IN are not capable of providing size-resolved information. Such knowledge is useful in identifying the sources of IN. The recently developed micro-orifice uniform deposit impactor-droplet freezing technique (MOUDI-DFT) provides size-resolved information by combining an established immersion freezing apparatus with a cascade impactor for sample collection. Here we show results from a field study undertaken at a remote coastal site in Western Canada in August, 2013 using this technique. The size distributions of IN will be presented. A recent study suggested that the IN population in remote marine regions might be dominated by primary biogenic particles. To address the sources of IN from this campaign, correlations between IN concentrations and biological aerosols, carbonaceous aerosols, and other possible IN sources will be discussed.