High time resolution measurements of peroxy acyl nitrates during OASIS

Principal Investigators:

Frank Flocke, Wengang Zheng
NCAR / ACD
ffl@ucar.edu

Department of Chemistry
University of Toronto
80 St. George St.
Toronto, ON M5S 3H6
Canada

Sponsorship: NSF / NCAR:

We will deploy a high time resolution Chemical Ionization Mass Spectrometer (CIMS) instrument to measure peroxy acyl nitrates (PANs) with a time resolution of 1-2 seconds (dep. on number of species) and a limit of detection between 1 and 5 pptv (dep. on species) during the OASIS experiment. The instrument will sample sequentially from three inlet heights mounted on a 20 foot tower to determine potential gradients and estimate fluxes of PANs from and to the snow surface. We are also planning to sample from the Balloon at three heights up to 500 feet above the surface to probe boundary layer gradients of PANs. 

PANs are important indicators for NOx – radical chemistry and ozone formation on a time scale of hours to days and they are also important as a transport medium for NOx throughout the troposphere. For the OASIS campaign, PANs will be important to help determine the fate of aldehydes, which may be emitted from the snowpack. PANs will also help to shed light on air mass origin and photochemical history of advected air masses.

Pan Man