DOAS Measurements

Three differential optical absorption spectrometers (DOAS) will be used to make long-path measurements over the Cornelia Fort site. EPA (McClenny) will operate a DOAS for NO₂ measurement on the Cornelia Fort site.

Two additional DOAS units will be operated by J. Stutz (UCLA) / B. Alicke and G. Hoenniger (Heidelberg). One unit will be located at Cornelia Fort Air Park, the second (pictured left) at the State of Tennesse Department of Health and Environment Laboratory on Heart Lane. The retro reflector for both spectrometers will be located on the roof of The Gaylord Entertainment Building on the East side of the Cumberland River in Nashville. The path length from the State Laboratory to Gaylord is 4-5 km, while the path length from Cornelia Fort to Gaylord is approximately 1 km. The species to be measured with the two instruments are as follows:

State Lab to Gaylord	NO3, NO2
Cornelia Fort to Gaylord	HONO, CH2O, O3, SO2, NO2