United States Atmospheric Sciences Research Environmental Protection Laboratory Agency Research Triangle Park NC 27711 Research and Development EPA/600/S8-86/027 Dec. 1986 SEPA Project Summary Addendum to TUPOS— Incorporation of a Hesitant Plume Algorithm D. Bruce Turner This Project Summary was devel- oped by EPA's Atmospheric Sciences Research Laboratory. Research Tri- angle Park, NC, to announce key findings of the research project that is fully documented in a separate report of the same title (see Project Report ordering information at back). The existence of non-Gaussian plume behavior within the convective boundary layer has been pointed out and recently discussed at a national conference. In such cases the buoyant forces within the plume, although unable to penetrate the inversion, both resist downward motion and result in increased horizontal spreading. Because of its hesitancy for downwind dispersion, the author is using "hesitant plume" to refer to the above plume behavior. Briggs has suggested convective scaling parameterizations for surface crosswind integrated concentra- tions. Combined with parameterization of the crosswind spreading and assuming that the horizontal diffusion is Gaussian, allows estimation of concentrations on the horizontal plane. This addendum makes changes to the TUPOS model (Turner et al., 1986) in order to better account for buoyant plumes that bump against, but do not penetrate, the inver- sion layer at the mixing height. The resulting algorithm isTUPOS-2.0. ------- The EPA author, Bruce Turner (also the EPA Project Officer, see below) is with Atmospheric Sciences Research Laboratory, Research Triangle Park, NC 27711. The complete report, entitled "Addendum to TUPOS—Incorporation of a Hesitant Plume Algorithm," (Order No. PB 86-241 031/AS; Cost: $9.95. subject to change) will be available only from: National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Telephone: 703-487-4650 The EPA Project Officer can be contacted at: Atmospheric Sciences Research Laboratory U.S. Environmental Protection Agency Research Triangle Park. NC 27711 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati OH 45268 Official Business Penalty for Private Use $300 EPA/600/S8-86/027 0000329 PS 60604 ------- |