9505386 Carroll The goal of this project is to obtain seasonal data on ozone and ozone precursors in order to determine (1) the climatology of these species, and (2) the photochemical and transport processes responsible for the formation and loss of ozone at a rural site in the midwest. Continuous measurements of ozone, carbon monoxide, temperature, relative humidity, wind speed, wind direction, and ultraviolet radiation, as well as measurements of nitric oxide, nitrogen dioxide, and total reactive nitrogen during four seasonal intensive periods will be conducted at the University of Michigan Biological station, located near the northern tip of Michigan's lower peninsula. The site chosen experiences continental polar and temperate continental and maritime air masses. The following techniques will be employed: ultraviolet absorption for ozone, non-dispersive infrared analysis for carbon monoxide, photolysis of nitrogen dioxide and catalytic conversion of total reactive nitrogen to nitric oxide, and detection of NO via chemiluminescence. A photochemical box model will be used to quantify in situ ozone formation at the site, and modeling studies will investigate the current understanding of photochemistry of regional transport events.
