Influence of ground surface characteristics on the mean radiant temperature in urban areas

• The effect of variations in land cover on mean radiant temperature (T-mrt) is explored through a simple scheme developed within the radiation model SOLWEIG. Outgoing longwave radiation is parameterised using surface temperature observations on a grass and an asphalt surface, whereas outgoing shortwave radiation is modelled through variations in albedo for the different surfaces. The influence of ground surface materials on T-mrt is small compared to the effects of shadowing. Nevertheless, altering ground surface materials could contribute to a reduction in T-mrt to reduce the radiant load during heat-wave episodes in locations where shadowing is not an option. Evaluation of the new scheme suggests that despite its simplicity it can simulate the outgoing fluxes well, especially during sunny conditions. However, it underestimates at night and in shadowed locations. One grass surface used to develop the parameterisation, with very different characteristics compared to an evaluation grass site, caused T-mrt to be underestimated. The implications of using high temporal resolution (e.g. 15 minutes) meteorological forcing data under partly cloudy conditions are demonstrated even for fairly proximal sites.

Subject headings

NATURVETENSKAP  -- Geovetenskap och miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences (hsv//eng)

Keyword

SOLWEIG

Surface temperature

Gothenburg

London

outdoor thermal comfort

solar-radiation

street canyon

energy

environments

fluxes

parameterization

freiburg

germany

summer

Publication and Content Type

ref (subject category)

art (subject category)