Ground surface materials and microclimates in urban open spaces

Microclimatic conditions in open spaces are affected, among other parameters, by the morphology of the urban tissue and by the properties of surfaces. This paper presents measured data of air and surface temperatures, wind speed and relative humidity, taken in June and August 05, in five open spaces, in the city of Thessaloniki, Greece, to examine the effects of different ground surface cover on the microclimates that develop in each area. The monitored spaces contain materials such as marble, stone, concrete, ceramic tiles and asphalt, as well as grass and water surfaces. Differences found within three areas and between two areas monitored simultaneously, reveal the effects of material and surface properties. Measurements of incident and reflected solar radiation were also taken for an estimation of the surfaces' albedo. The monitored data is also used for the calibration of two software tools, ENVI-met v3.0 and RadTherm v8.0, to evaluate the possibility of a further examination, through simulations, of a wider range of open spaces, as well as of seasonal variations.