Influence of Global Sources on Free Tropospheric Ozone and Aerosols in the Western United States

University Of Washington, Seattle WA

Investigators

Abstract

This project involves quantification of trace gases and aerosols with the goal to better define sources of these species contained in air masses transported to the western continental boundary of North America. The study will develop and make use of a new atmospheric measurement site on the summit of Mt. Bachelor in central Oregon. The 2.7 km altitude will likely enable regular sampling of free tropospheric air masses much as other mountain sites (for example, Mauna Loa Observatory, Hawaii, and Izana Atmospheric Observatory, Canary Islands). This will allow assessment of the contributions of long range transport of emissions to the regional budgets of ozone and fine particles. During the study period, continuous measurements of ozone, carbon monoxide, and condensation nuclei concentrations, as well as aerosol light scattering efficiencies, will be made. During specific campaign periods, the measurement suite will be enhanced to include reactive nitrogen compounds (nitric oxide, nitrogen dioxide), peroxyacetyl nitrate (PAN), and the tracers of air mass origin, beryllium-7 and lead-210. Aircraft based concentration profiles of selected species and satellite based observations will be used to set the surface based measurements in horizontal and vertical context. A global chemical transport model will be used to help establish budgets and quantify the contributions from remote sources. This project will establish a new atmospheric observing site at an altitude useful for atmospheric studies with a variety of goals. In this project, the data derived from the site will be useful for quantifying the role of long range transport on budgets of important tropospheric species such as ozone and fine particles. The project will also involve training of a post-doctoral research fellow and an undergraduate student. A community college faculty member will also be involved in the project.