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.

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       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
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