Extended Abstract (140K)7.3
Validation of modelled mean radiant temperature within urban structures
Andreas Matzarakis, University of Freiburg, Freiburg, Germany
For the human-biometeorological evaluation of the thermal component of urban and regional climate, precise and high resolution radiation data of the whole surrounding of people are necessary.
The most important meteorological parameter influencing the energy balance of humans during sunny conditions in summer is the mean radiant temperature. It defines the uniform temperature of a surrounding surface giving off blackbody radiation which results in the same energy gain of a human body given the prevailing radiation fluxes. The latter usually vary considerably under open space conditions.
The mean radiant temperature can either be obtained from separate measurements of solar (short wave) and terrestrial (long wave) radiation fluxes or by integral measurements. Here the methods of measuring mean radiant temperature as well as problems associated with the accuracy of the input data for estimation purposes are discussed.
The model „RayMan“ for the calculation of shortwave and longwave radiation fluxes on the human body is presented. The model estimates the radiation fluxes and the effects of clouds on shortwave radiation fluxes. The model which considers complex urban structures is suitable in urban areas. The final output of the model is, however, the calculated mean radiant temperature which is required in the energy balance model for humans and the derived thermal indices.
Results emanating from the model are validated with the results from micro-meteorological measurements in urban areas, particularly in Freiburg. This validation shows that the calculated mean radiant temperature by the use of RayMan agree with measured values. The calculation of radiation fluxes in complex structures by RayMan is an easy way obtaining data for the thermal component of urban climate.
Session 7, Urban biometeorology
Tuesday, 21 May 2002, 2:15 PM-4:28 PM
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