AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Field Deployment of a Size-Resolved Nano CPC Battery to Infer the Composition of Freshly Formed Atmospheric Nuclei in the Boreal Forest
CHONGAI KUANG, Juha Kangasluoma, Daniela Wimmer, Katrianne Lehtipalo, Jian Wang, Markku Kulmala, Tuukka Petäjä, Brookhaven National Laboratory
Abstract Number: 496 Working Group: Advances in the Physics and Chemistry of New Particle Formation and Growth
Abstract Atmospheric particle nucleation is an important environmental nano-scale process, with field measurements and modeling studies indicating that freshly nucleated particles can contribute significantly to the global population of cloud condensation nuclei. Our understanding of atmospheric nucleation and its influence on climate, however, is limited, as few ambient measurements have been made of either the nucleation rate or the chemical composition of the freshly formed clusters, both of which are necessary to gain process-level understanding. Recently, a nano condensation particle counter battery (nano CPCb) was developed and characterized in the laboratory to infer the size-resolved composition of nanoparticles down to diameters of 1 nm. The nano CPCb is composed of CPCs optimized for the detection of sub 3 nm particles, using diethylene glycol, water, and butanol as the working fluids. The nano CPCb was also integrated as a particle detector in a Nano-SMPS (scanning mobility particle spectrometer) system optimized for nanoparticle detection down to 1 nm. By sampling mobility-classified particles, the nano CPCb accounts for the strong dependence of CPC detection on particle size and charge below 3 nm, so that any measured differences in CPC response can be attributed to composition-specific interactions between the particle and the various working fluids. The integrated system was then deployed during an intensive field campaign in the Spring of 2013 to study atmospheric nucleation and initial growth at a long-term measurement site in the boreal forest in Hyytiälä, Finland. Preliminary measurements of freshly nucleated aerosol size distributions will be presented, along with the corresponding size-resolved composition-dependent responses of the nano CPCb.