A Field Sampling of Jet Exhaust Aerosols

A mobile aerosol sampling facility was installed and operated on the NCAR (National Center for Atmospheric Research) Sabreliner high altitude research aircraft, for the purpose of sampling aerosols related to cirrus cloud phenomena. During this project the opportunity arose to do field sampling on jet exhaust aerosols, and these results are reported here. Aerosol properties sampled include concentration, size distribution, and hydration properties. The aerosol sampling facility features two electrostatic aerosol classifiers (EAC\u27s), in tandem, with a saturator in between. The saturator allows the aerosol to be equilibrated at 100% relative humidity between sizings with the EAC\u27s. The facility occupies about the space of two short equipment racks on the aircraft, and collects samples through a tube projecting through the aircraft skin. Exhaust samples were taken from Pratt and Whitney PT 6-42, JT 12A-8, and JT 15-D-4 engines, all burning Jet-A fuel. The results indicate that aerosol sampling offers a real time means of detecting and tracking jet exhaust plumes, even in the absence of visible smoke or ice contrails. A good correlation is found between engine exhaust aerosol properties and those generated in laboratory combustors. This cirrus aerosol field sampling program was done in support of the NASA/NOAA project FIRE (First ISSCP (International Satellite Cloud Climatology Project) Regional Experiment)