AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
A Scanning Mobility Particle Sizer for Nanoparticle Size Distribution Measurements in the Upper Troposphere/Lower Stratosphere
JOHN ORTEGA, James N. Smith, David C. Rogers, Suresh Dhaniyala, Steve Gabbard, National Center for Atmospheric Research
Abstract Number: 718 Working Group: Instrumentation and Methods
Abstract A Scanning Mobility Particle Sizer (SMPS) was recently developed for use in airborne measurements on board the two aircraft operated by the National Center for Atmospheric Research: the C-130 and the Gulfstream V (GV). The latter aircraft can fly at altitudes above 45,000 ft. (~13,700 m), in the upper troposphere/lower stratosphere, requiring precise control of gas flows at pressures ranging from ~15 kPa to atmospheric pressure. One of the limitations of using a commercial Differential Mobility Analyzer (DMA) at low pressures is electrical discharge that occurs at the highest applied voltages. To address this, we have modified a TSI 3085 nano-DMA to eliminate electrical discharges at up to 10 kV at reduced pressures. The SMPS is configured to obtain a complete size distribution, from ~ 7nm to 390 nm, over a scan time of one minute. The instrument was successfully deployed on the GV during the Deep Convection Clouds and Chemistry (DC3) Experiment in the summer of 2012, and will participate in NOMADSS (Nitrogen, Oxidants, Mercury and Aerosol Distrubutions, Sources and Sinks) on board the C130 in 2013. This presentation will focus on instrument development, performance, and several scientific results (including size distributions, new particle formation, in-cloud sampling artifacts, and particle growth) from these campaigns.