For an edited transcript of the video, click here.The Atmospheric Turbulence and Diffusion Division (ATDD), located in Oak Ridge, Tennessee, is one of several field divisions of NOAA’s Air Resources Laboratory. ATDD was originally created to develop diffusion models to track the dispersion of accidental releases of contaminants (see the ATDD History page). This research led to participation in scientific campaigns investigating atmospheric flows in complex terrain and urban areas and the transport and surface exchange of nitrogen, sulfur, and mercury compounds. ATDD is still involved in surface-atmosphere exchange research and how these processes affect atmospheric behavior, weather, climate and air pollution. ATDD’s research is focused on air quality, climate and boundary-layer processes and is directed toward issues of national and global importance. Air quality research objectives include improving the understanding of air-surface exchange processes and increasing the predictive capabilities of air quality models. Climate research objectives include the reference-grade measurement of climate change variables and related physical and chemical processes. ATDD maintains NOAA’s Climate Reference Network, which includes designing, testing, installing and maintaining precision monitoring stations in all 50 states. Boundary-layer research objectives include the measurement of lower atmospheric processes related to surface-atmosphere energy exchanges and turbulent transport of moisture, momentum and chemical constituents. ATDD has a permanent staff of approximately 40 personnel, and frequently hosts graduate- and undergraduate students, post-doctoral fellows, and U. S. and international visiting scientists for varying intervals. Research at ATDD is performed in collaboration with other NOAA laboratories, government agencies, universities and private organizations. We operate two permanent research stations, one at the Department of Energy (DOE) Oak Ridge National Laboratory Walker Branch Watershed forested experimental area, and one on the DOE reservation at the Chestnut Ridge Environmental Study site. Important on-site facilities include a wind tunnel laboratory, machine shop, electronics laboratory, and chemical instruments laboratory.