Evidence for diverse biogeochemical drivers of boreal forest new particle formation
Authors
Michael Joseph Lawler — University of Colorado, Boulder
Matti Rissanen — Department of Physics
Mikael Ehn — University of Helsinki
Roy Leon Mauldin — University of Colorado, Boulder
Mikko Sipilä — University of Helsinki
Jeffrey Robert Pierce — Colorado State University
James Smith — University of California, Irvine
Category
ARM field campaigns – Results from recent ARM field campaigns
Description
New particle formation is an important contributor to particle number in many locations, but the chemical drivers for this process are not well-understood. Daytime new particle formation events occur regularly in the springtime Finnish boreal forest and strongly impact aerosol abundance. During the Biogenic Aerosols - Effects on Clouds and Climate (BAECC) experiment in Hyytiälä, Finland, during April 2014, size-resolved measurements of ambient nanoparticle chemical composition were made using the Time-of-Flight Thermal Desorption Chemical Ionization Mass Spectrometer. We report results from two new particle formation events. While growth overall was dominated by terpene oxidation products, newly formed 20-70 nm diameter particles showed enhancement in apparent alkanoic acids. The events occurred on days with rapid transport of marine air, which correlated with low background aerosol loading and higher gas phase methanesulfonic acid levels. These results are broadly consistent with previous studies on Nordic new particle formation but indicate that further attention should be given to the sources and role of non-terpenoid organics and the possible contribution of transported marine compounds in this process.
