Overview of URBAN 2000: A Multiscale Field Study of Dispersion through an Urban Environment

Abstract

A major urban tracer and meteorological field campaign (URBAN 2000) was conducted in Salt Lake City, Utah, during October 2000. Sponsored by the U.S. Department of Energy's (DOE's) Chemical and Biological National Security Program, the month-long field campaign received supplemental support (personnel and equipment) from other U.S. and foreign government agencies and private companies. Seven nighttime intensive experiments were designed to resolve, with both inert tracers and meteorological measurements, interacting scales of atmospheric motion from the individual building scale up through the urban scale. Scale interaction was extended beyond the urban scale to the regional scale by embedding the URBAN 2000 study in DOE's Vertical Transport and Mixing Program tracer and meteorological studies conducted simultaneously in the greater Salt Lake Valley. Results from the URBAN 2000 study will be used to evaluate and improve the hierarchy of atmospheric models being developed for simulating toxic agent dispersal from potential terrorist activities in urban environments. In addition, the results will be used to identify and further understand the meteorological and fluid dynamic processes governing dispersion in urban environments. The strength of the URBAN 2000 study is that it provides a dataset that resolves interacting scales of motion from the individual building up through the regional scale under the same meteorological conditions. This paper summarizes the URBAN 2000 study by describing the experimental design, instrument layout, experiments, and meteorological conditions investigated. The paper also discusses initial findings.