Particulate Transport During ICARTT-ITCT-2K4: Aerosol Characterization from Time-Resolved and Size-Segregated Continuous Sampling and Analysis

Continuous aerosol sampling and analysis during the Intercontinental Transport and Chemical Transformation Experiment of 2004 (ITCT-2K4) at Chebogue Point, Nova Scotia and Acadia National Park revealed both synoptic-scale particulate transport and evidence of local aerosol transformation processes. These sites are approximately 100 km apart separated by the Bay of Maine. We collected aerosol for approximately 42 days during June-August 2004 at each site using an 8-stage continuously Rotating DRUM Impactor (8-RDI) and subsequently analyzed the samples with synchrotron sourced x-ray fluorescence for elements and beta attenuation analysis for mass. Each analysis technique is capable of at least 3-hour ambient resolution for the 6-week collection period. Analysis of the resultant data indicates periods in early July and mid-August characterized by transport of North American particulate pollution bracketing periods of locally characteristic aerosol behavior (i.e. continental influenced at Acadia and marine influenced at Chebogue Point). Comparison of elemental ratios and statistical compositional association of the sampled aerosol provide evidence of transport during the ITCT-2K4 study. In addition to mass, 18 elements are well quantified (i.e. signal/noise ratio greater than 3) at both sites and are used in the statistical analysis. The Acadia National Park sampling was coincident with the Interagency Monitoring of Protected Visual Environments (IMPROVE) site. An approximately 10-year record of aerosol data exists for this site to put the ITCT-2K4 sampling in context. An analysis of historical meteorology and compositional data from Acadia N.P. reveals periods of regional (i.e. North American) and hemispheric-scale pollution transport to the site. Particle characteristics, elemental and mass composition and statistical data analysis of the Acadia N.P. and Chebogue Point samples will be presented.