Abstract
The model developed in Verseghy and Munro (1989) is extended to the calculation of the longwave radiation incident on building surfaces. When compared with field measurements, the average magnitude of error associated with model predictions is found to be 10 W m−2. The effects of six simplifying assumptions are investigated. The neglect of horizon obstructions is found to lead to errors of up to 60 W m−2; the assumption of wall temperatures equal to air temperatures results in errors of up to 35 W m−2. The neglect of absorption and emission by air between pairs of walls causes errors of the same magnitude as those associated with the predictions of the rigorous model itself. Of the three remaining simplifying assumptions tested (the assumption of isotrophic sky radiation, the use of published values of emissivities instead of measured values, and the blackbody surface assumption), none results om errors >5 W m−2. As in the shortware case, the errors are site-specific, but nevertheless indicate the care with which the use of simplifying assumptions must be approached.
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References
ASHRAE: 1977, Handbook of Fundamentals, American Society of Heating, Refrigerating and Air-Conditioning Engineers, New York, 756 pp.
Arnfield, A. J.: 1976, ‘Numerical Modelling of Urban Surface Radiative Parameters’, in Papers in Climatology — The Cam Allen Memorial Volume, McMaster University, Hamilton, Canada, 141 pp.
Buettner, K. J. K. and Kern, C. J.: 1965, ‘The Determination of Infrared Emissivities of Terrestrial Surfaces’, J. Geophys. Res. 70, 1329–1337.
Cole, R. J.: 1979, ‘The Longwave Radiation Incident upon Inclined Surfaces’, Solar Energy 22, 459–462.
Hare, F. K. and Thomas, M. K.: 1979, Climate Canada, Wiley, Toronto, 230 pp.
Kondratyev, K. Ya.: 1969, Radiation in the Atmosphere, Academic Press, New York, 912 pp.
Martin, M. and Berdahl, P.: 1984, ‘Summary of Results from the Spectral and Angular Sky Radiation Measurement Program’, Solar Energy 33, 241–252.
Oke, T. R.: 1978, Boundary-Layer Climates, Methuen, London, 372 pp.
Oke, T. R.: 1982, ‘The Energetic Basis of the Urban Heat Island’, Quart. J. Roy. Meteorol. Soc.108, 1–24.
Sellers, W. D.: 1965, Physical Climatology, University of Chicago Press, Chicago, 272 pp.
Siegel, R. and Howell, J. R.: 1981, Thermal Radiation Heat Transfer, McGraw-Hill, New York, 862 pp.
Staley, D. O. and Jurica, G. M.: 1970, ‘Flux Emissivity Tables for Water Vapour, Carbon Dioxide and Ozone’, J. Appl. Meteorol. 9, 365–372.
Sutherland, R. A. and Bartholic, J. F.: 1977, ‘Significance of Vegetation in Interpreting Thermal Radiation from a Terrestrial Surface’, J. Appl. Meteorol. 16, 759–763.
Todhunter, P. E. and Terjung, W. H.: 1988, ‘Intercomparison of Three Urban Climate Models’, Boundary-Layer Meteorol. 42, 181–205.
Unsworth, M. H. and Monteith, J. L.: 1975, ‘Long-wave Radiation at the Ground: I. Angular Distribution of Incoming Radiation’, Quart. J. Roy. Meteorol. Soc. 101, 13–24.
Verseghy, D. L.: 1987, On the Measurement and Modelling of Radiative Exchange for Building Surfaces, unpublished Ph.D thesis, University of Toronto, Toronto, 170 pp.
Verseghy, D. L. and Munro, D. S.: 1989, ‘Sensitivity Studies on the Calculation of the Radiation Balance of Urban Surfaces: I. Shortwave Radiation’, Boundary-Layer Meteorol. 46, 343–365.
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Verseghy, D.L., Munro, D.S. Sensitivity studies on the calculation of the radiation balance of urban surfaces: II. Longwave radiation. Boundary-Layer Meteorol 48, 1–18 (1989). https://doi.org/10.1007/BF00121780
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DOI: https://doi.org/10.1007/BF00121780