Multi-year Chemistry of Particles and Selected Trace Gases at the Whistler High Elevation Site

Measurements will be presented from a high elevation site in Whistler, British Columbia. The site was established in spring 2002 and a three year pilot study was completed in spring 2005. The primary objectives of the pilot study were to establish a database of background chemistry in the lower free troposphere and to provide information on incursions of pollution transported across the Pacific and into North America. Measurements at Whistler Peak (elevation 2182 m-asl) include the trace gases carbon monoxide and ozone. Aerosol particles (< 2.5 microns) have been analyzed for a suite of inorganic compounds. Particle size distributions over the size range of 10 nm to 20 microns have been made with a differential mobility analyzer and an optical particle counter. Standard meteorological parameters are also available at the site. A discussion of the influence of the free troposphere or the planetary boundary layer at the site will first be presented. Results will then include seasonal cycles in CO and ozone and the interannual variability of their mixing ratios; and the size distributions of the background aerosol. The soluble inorganic composition of the aerosol particles as determined from filter packs will be related to total particle mass as determined from the DMA and OPC. This will then be discussed in relation to detailed aerosol chemical measurements made on- site by an Aerosol Mass Spectrometer during one month in spring 2005.