Lagrangian Long Range Air Pollution Model for Eastern North America

The transport of airborne sulfur and nitrogen compounds and their deposition on the earth’s surface by dry and wet processes have been simulated using Lagrangian numerical models developed at SRI over the past several years. The EURMAP model (Johnson et al., 1978; Bhumralkar et al., 1981, 1982) developed under sponsorship of Umweltbundesamt of the Federal Republic of Germany, applies to Europe; and the ENAMAP model (Bhumralkar et al., 1980; Mayerhofer et al., 1981; Endlich et al., 1982), developed under sponsorship of EPA, applies to eastern North America. Emissions data are obtained for the areas of interest and are represented on a grid mesh with spacing of 50 km for Europe and 70 km for North America. The computations are based on grid-point analyses of winds, stability, and precipitation made from standard meteorological reports, and thereby incorporate the effects of changing weather patterns. The most recent versions of the models use three layers in the vertical and correct the winds for the influences of smoothed terrain (Bhumralkar et al., 1982; Endlich et al., 1982).