12.1
Urban effects on atmospheric transport and mixing determined from the URBAN 2000—VTMX tracer studies
PAPER WITHDRAWN
K. Jerry Allwine, PNNL, Richland, WA; and J. D. Fast, K. L. Clawson, and R. N. Dietz
The U.S. Department of Energy (DOE) sponsored major meteorological and tracer field campaigns in the greater Salt Lake Valley during October 2000. Scientists within two DOE programs collaborated to investigate a wide range of scales-of-motion governing dispersion and vertical transport in the atmospheric boundary layer. The Chemical and Biological National Security Program (CBNP) within the Office of Nonproliferation Research and Engineering focused on the building to urban scale and DOE’s Vertical Transport and Mixing (VTMX) Program in the Environmental Meteorology Program within the Office of Science focused on the urban to regional scale. Five inert atmospheric tracers were released for several hours simultaneously within the Salt Lake Valley on seven nights during October. Three tracers (sulfur hexafluoride and two perfluorocarbon –PFT) were released from around downtown Salt Lake City and two PFTs were released from two locations several kilometers south of Salt Lake City. Tracer concentrations were measured at over 150 locations covering downtown Salt Lake City and extending throughout the Salt Lake Valley. This paper gives the tracer concentration patterns and evolution of the patterns throughout Salt Lake City and the surrounding Salt Lake Valley. The effects of the urban area on atmospheric diffusion rates and vertical mixing are discussed. Four tracers were released at ground-level at various elevations and one tracer was release from a building top in downtown Salt City. These different tracer release heights allowed for vertical mixing rates to be investigated directly. The vertical mixing rates determined from the tracer data are also discussed.
Session 12, Urban field projects: URBAN-VTMX
Thursday, 23 May 2002, 1:30 PM-3:44 PM
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