Regional nocturnal tracer experiment near a tall tower site

The Savannah River National Laboratory (SRNL), Brookhaven National Laboratory (BNL), the University of Georgia (UGA), and the National Oceanic and Atmospheric Administration (NOAA) conducted a regional tracer experiment to study the nocturnal behavior of CO2 in the vicinity of an instrumented tall tower during two nights on May 11th and 12th 2009. The experiment consisted of a release of five perfluorocarbon tracer (PFTs) compounds in twelve unique locations in Aiken County South Carolina. Intensive meteorological measurements including in-situ turbulence and remote sensors were made in conjunction with the release and spatial and vertical sampling of the PFTs. The measurements were centered on an instrumented 300m television transmission tower that is currently the site of long term trace gas measurements conducted by NOAA's Global Monitoring Division. The experiment was specifically designed for winds from the northeast quadrant of the site to take advantage of similar foliage and topography around the tall tower. Tracer release locations were carefully selected via a fine-scale mesoscale modeling study of similar nights. The purpose of these experiments was to provide data that will be used to increase the understanding of the terrestrial carbon budget especially with respect to nocturnal boundary layer phenomena such as low level jets and breaking gravity waves. Preliminary findings from these experiments will be presented.