Measurement of Particle Concentrations above a Forest and Surrounding Farmland

Very little information is currently available regarding the spatial scales on which nucleation occurs in the near surface layer. As part of the May 2008 Nucleation In ForesTs (NIFTY) campaign, an unmanned aerial vehicle (UAV) system was flown across the study area of the Morgan-Monroe State Forest (MMSF). The Clarkson Vector-P UAV carried a TSI Model 3007 Condensation Particle Counter (CPC) and a Grimm Model 1.109 Universal Aerosol Spectrometer (UAS). The CPC provides the count of ultrafine particles while the UAS gives counts of large particles (0.25 to 20 "Ým). These measurements were designed to supplement the extensive measurements being made on the 46 m instrumented tower. Because of the FAA restrictions of line-of-sight observation of the UAV by ground observers, we were limited in the spatial extent and were limited to studying altitudes below 1200 feet. However, these restrictions still permitted us to make a series of measurements of the spatial and vertical extent of particle concentrations to support the ground level composition measurements to better understand nucleation and growth in this rural area of southwestern Indiana.