Numerical Modeling Of AtmosphericDispersion During The MOHAVE Field Study

Abstract

The design of daily meteorological and dispersion simulations for the MOHAVE project is presented. These simulations are being performed at CSU for a year long study using the CSU Regional Atmospheric Modeling System (RAMS) coupled with a Lagrangian particle dispersion model. INTRODUCTION The Measurement Of Haze And Visual Effect (MOHAVE) program is a year long field study being conducted in the desert southwest United States to assess the impact of the Mohave Power Project (MPP) and other potential sources of air pollution to specific Class I areas located in the region. The measurement phase of this study was conducted between September 1, 1991 and August 31, 1992. The intensive periods of the study (one during winter and one during summer) included the release of a perfiuorocarbon (PFT) tracer from MPP. The Colorado State University team is participating in the modeling component of the project using a non-hydrostatic mesoscale meteorological model (RAMS) coupled with a Lagrangian particle dispersion (LPD) model. The modeling domain covers the southwestern United States with its extremely complex terrain. Daily meteorological simulations are being performed with the RAMS on two nested grids. Sourceand receptor-oriented approaches are being used as complementary tools for dispersion modeling. The goal of this paper is to present our design of the daily meteorological and dispersion simulations which are currently being performed at CSU for a year long study. All computations are being performed on two IBM RISC-6000 workstations dedicated to the project. METEOROLOGICAL SIMULATIONS The meteorological model being used in this study was initially a combination of two different models. The first, originally developed by Pielke [4] and imTransactions on Ecology and the Environment vol 1, © 1993 WIT Press, www.witpress.com, ISSN 1743-3541