Abstract
Particulate dispersion from sources within a 10- to 13-m tall pine forest was studied experimentally at Brookhaven National Laboratory using stained ragweed pollen and other tracers ranging from 14 to 58 Μm in size. Forty-seven continuous point source releases lasting from 22 to 55 min were made at heights from 1.75 to 14.0 m from locations having a long fetch through the forest. In most experiments, differently colored ragweed pollen were emitted simultaneously from three locations. In other tests, several particle types were released from a single point. The sampling network consisted of 119 rotoslide samplers at heights from 0.5 to 21.0 m at 57 positions within and at the edge of the forest. Deposition to the ground was sampled by greased microscope slides at each position. Meteorological measurements were taken in and near the forest.
Data were classified by particle characteristics, source height and meteorological parameters. Concentration patterns were illustrated on scale diagrams of the sampling grid. Changes in centerline and crosswind integrated concentrations, plume width and height, mass flux, deposition and deposition velocity were studied as a function of distance, particle size and wind speed. Results were compared to those obtained from similar releases over open terrain.
In the forest, vertical predominates over lateral dispersion and considerable interchange occurs through the canopy. Flow is channelled somewhat by vegetation density differences but is generally in the direction of the mean wind above the forest. No systematic turning of the wind with height was observed. Most particles are lost to the foliage rather than to the ground and large particles are lost more rapidly than smaller ones. Rate of change in mass flux is similar to that over open terrain and is greater with light than with stronger wind speeds.
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References
Barr, S.: 1971, A Modeling Study of Several Aspects of Canopy Flow, Monthly Weather Rev. 99, 485–493.
Calder, K. L.: 1961, A Simple Mathematical Model for the Penetration of Forest Canopy by Aerosols, BL Tech. Study 37, U.S. Army Chem. Corps, Fort Detrick, Md. AD262228, Armed Services Tech. Info. Agency, Arlington, Va., 30 pp.
Cionco, R. M.: 1965, A Mathematical Model for Air Flow in a Vegetative Canopy, J. Appl. Meteorol. 4, 517–522.
Ford, E. F. and Lomen, D. O.: 1969, Diffusion Under a Jungle Canopy. Final Report, Volume III - Mathematical Model. Melpar, Inc., Falls Church, Va., 124 pp.
Fritschen, L. J., Driver, C. H., Avery, C., Buffo, J., Edmonds, R., Kinerson, R., and Schiess, P.: 1970, Dispersion of Air-Tracers into and within a Forested Area: 3, Res. and Devel. Tech. Rept. ECOM-68-G8–3, U.S. Army Electronics Command, Fort Huachuca, Ariz., 53 pp.
Kinerson, R. S., Jr. and Fritschen, L. J.: 1973, Modeling Air Flow through Vegetation, Agric. Meteorol. 12, 95–104.
Melpar, Inc.: 1968, Diffusion Under a Jungle Canopy, Vol. 1, Main report. Melpar, Inc., Falls Church, Va., 176 pp.
Meroney, R. N.: 1968, Characteristics of Wind and Turbulence in and above Model Forests, J. Appl. Meteorol. 7, 780–788.
Meroney, R. N. and Yang, B. T.: 1969, Wind Tunnel Studies of the Air Flow and Gaseous Plume Diffusion in the Leading Edge and Downstream Regions of a Model Forest, Tech. Rept. ECOM C-0423–6, Colorado State Univ., Ft. Collins, Colo., 63 pp.
Ogden, E. C. and Raynor, G. S.: 1967, A New Sampler for Airborne Pollen: The Rotoslide, J. Allergy 40, 1–11.
Plate, E. J., and Quraishi, A. A.: 1965, Modeling of Velocity Distributions Inside and Above Tall Crops, J. Appl. Meteorol. 4, 400–408.
Raynor, G. S.: 1971, Wind and Temperature Structure in a Coniferous Forest and a Contiguous Field, Forest Sci. 17, 351–363.
Raynor, G. S. and Smith, M. E.: 1964, A Diffusion-Deposition Tracer System, Report BNL 859 (T-343), Brookhaven National Laboratory, Upton, N.Y., 17 pp.
Raynor, G. S., Ogden, E. C., and Hayes, J. V.: 1970, Dispersion and Deposition of Ragweed Pollen from Experimental Sources, J. Appl. Meteorol. 6, 885–895.
Raynor, G. S., Hayes, J. V., and Ogden, E. C.: 1972, Experimental Data on Particulate Dispersion into and Within a Forest. Part I. Dispersion from Upwind Point Sources, Informal Report BNL 17750, Brookhaven National Laboratory, Upton, N.Y., 95 pp.
Raynor, G. S., Hayes, J. V. and Ogden, E. C.: 1974a, Experimental Data on Particulate Dispersion into and Within a Forest. Part III. Dispersion from Sources Within and Above the Forest, Informal Report BNL 19474, Brookhaven National Laboratory, Upton, N.Y., 48 pp.
Raynor, G. S., Hayes, J. V. and Ogden, E. C.: 1974b, Particulate Dispersion Into and Within a Forest, Boundary-Layer Meteorol. 7, 429–456.
Raynor, G. S., Cohen, L. A., Hayes, J. V., and Ogden, E. C.: 1966, Dyed Pollen Grains and Spores as Tracers in Dispersion and Deposition Studies, J. Appl. Meteorol. 5, 728–729.
Shinn, J. H.: 1968, Air Flow in the Tree Trunk Region of Several Forests, Presented at National Meeting of Am. Meteor. Soc. with Pacific Div., Am. Assoc. for the Advancement of Sci., Logan, Utah, June 26–28, 1968, 30 pp.
Singer, I. A. and Smith, M. E.: 1953, Relation of Gustiness to Other Meteorological Parameters, J. Meteorol. 10, 121–126.
Smith, F. B., Carson, D. J., and Oliver, H. R.: 1972, Mean Wind Direction Shear Through a Forest Canopy, Boundary-Layer Meteorol. 3, 178–190.
Tourin, M. H. and Shen, W. C.: 1969, Deciduous Forest Diffusion Study. Final Report, Vol. 1, Diffusion Studies in a Deciduous Forest, Report No. 3004, Litton Systems, Inc., Minneapolis, Minn., 325 pp.
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This research was carried out under the auspices of the New York State Museum and Science Service and the U.S. Atomic Energy Commission (now Energy Research and Development Administration) and was partially supported by Research Grant No. R-800677 from the Division of Meteorology, U.S. Environmental Protection Agency.
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Raynor, G.S., Hayes, J.V. & Ogden, E.C. Particulate dispersion from sources within a forest. Boundary-Layer Meteorol 9, 257–277 (1975). https://doi.org/10.1007/BF00230770
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DOI: https://doi.org/10.1007/BF00230770