Comparison of the time evolved spatial distribution of urban PM2.5 concentrations during burning and wind-blown high PM events in Yuma, AZ

A field study designed to investigate the spatial and temporal variability of atmospheric aerosols during high particulate matter (PM) events along the US/Mexico border near Yuma, AZ was run during the week of March 18, 2007. The experiments were designed to quantify chemical composition and physical phenomena governing the transport of aerosols generated from burning or high wind events. The field study included two micrometeorological monitoring sites; one rural and one urban, equipped with sonic anemometers, continuous particulate concentration monitors and ambient aerosol collection equipment. In addition to the two main monitoring sites, six additional locations were equipped with TSI DustTrak monitors to allow for the investigation of the spatial and temporal distribution of PM2.5 concentrations in the urban environment. All DustTrak devices were collocated with Beta-Attenuation Mass (BAM) monitors deployed by the Arizona Department of Environmental Quality. The meteorological and turbulent parameters governing the distribution and concentration of PM2.5 in the urban environment for a high wind crustal dust event will be compared to a low wind stble atmosphere burning event that originated near the border. The interaction between local atmospheric conditions and the particulate distribution and mixing will be investigated. Plume statistics for the burn event will be evaluated to determine if a Gaussian plume simulation can accurately predict the particulate concentrations and distribution to assist in identifying the source location. A comparison of the chemical composition (determined using X-ray fluorescence) of atmospheric aerosols for the two events will be presented using principle component analysis of inorganic elements. The comparison of inorganic species will provide further information to differentiate between the burning and wind-blown high PM events.