The effect of various types of radiation shields on climate indices measured by urban stations; extensive inter-comparison study in Ostrava, Czech Republic

Urban climate research literature of the last two decades responded to the more intensive utilization of urban measurement networks with a higher focus on measurement quality, data control, sensor accuracy, station placement, and representativeness of the location in various scales. However, in urban climate research, considerably only a minor amount of attention has been devoted to the role of radiation shields in measurement results. In this study, we analyze three years of experimental field co-location in the meteorological garden located in the urban environment of Ostrava (Czech Republic). The aim was to investigate the effect of 16 various radiation shields on mean, minimal, and maximal daily temperatures and climate indices. Moreover, the extent of influence of radiation shield type on characteristics frequently reported in urban climate research was discussed. We found significant differences between the same sensors under different radiation shields, which correspond to the type and colour of the shield. The differences are often not linear and vary with daytime and seasons. In several types of shields, the maximal daily temperature is substantially overestimated, whereas the minimal daily temperature is slightly underestimated. Consequently, the derived values of summer climate indices based on measurements with radiation shields commonly used in urban climate research can be substantially overestimated, as was confirmed in parallel research in Prague. Further research should focus on the role of different urban surfaces in the temperature differences between commonly used radiation shields.