Modelled spatio-temporal variability of air temperature in an urban climate and its validation: a case study of Brno, Czech Republic

Abstract

This study compares the results of air temperature model simulations with real temperature measurements in an urban environment. The non-hydrostatic micro-scale model MUKLIMO_3 is used to predict air temperature fi elds in Brno (Czech Republic). The development of the air temperature fi elds on three diff erent days was modelled which characterising the radiation-driven weather conditions with high temperature that occurred during the summer of 2015. This analysis demonstrates that the model is able to reproduce the spatial distribution of the air temperature during the day. Statistical tests were applied to establish whether signifi cant diff erences exist between the modelled and measured air temperatures. Verifi cation of the model results against real temperature measurements was performed at fi ve meteorological stations. The mean absolute diff erences between the simulated and measured daily mean temperatures were 0.7 °C (4 July), 0.6 °C (18 July) and 0.5 °C (28 August), respectively. This demonstrates that the model overestimated the real values, however, not all the diff erences were statistically signifi cant. Moreover, there were no signifi cant diff erences in the variability of the temperatures that were compared. This study also shows that the proper defi nition of Local Climate Zones and their parameters is critical for more precise model performance.

Visualising a comparison of simulated urban heat islands: a case study of two Slovakian cities

“…This overestimation was clear in comparisons of model and measurements temperatures (Figure 7). This model attribute was reported previously by Geletič et al (2016). The only station with good nocturnal fitting was B4.…”

“…It also uses categorisations of proportions of surfaces of varied kinds using an established scale: built-up, impermeable, and permeable surface parts such as vegetation cover and soil (Sievers et al, 1983). The model has been used for UHI studies in various cities, for example, Vienna (Žuvela et al, 2014), Brno (Geletič et al, 2016(Geletič et al, , 2018, Bratislava (Holec and Šťastný, 2017), Szeged (Gál and Skarbit, 2017) or comparison of five central European cities (Bokwa et al, 2015;Bokwa et al, in print). Several model inputs are necessary, including layers of a digital elevation model, a LC/LU map, parameters of LC/LU classes, and meteorological inputs.…”

Land Surface Temperature Differences within Local Climate Zones, Based on Two Central European Cities

“…For instance, Alexander et al [15] revealed distinctive heat fluxes for some LCZs and concluded that LCZ classification provides a useful sampling framework for the derivation of the land-cover fractions needed to run surface-energy balance models. Zuvela-Aloise et al [16] and Geletič et al [17] used LCZs as input to MUKLIMO_3, a non-hydrostatic micro-scale air temperature model. Further, Skarbit et al [18,19] worked on the relations between LCZ and LST.…”

“…However, such measurements, even supplemented by measurements from a dense network of automatic stations, often prove insufficient to describe and understand fully the spatial variability of air temperature in urban areas [17,20]. These measurements are insufficient especially in terms of their ability to characterize temperature spatial distribution in detail, as the result may be dependent on the number of "point" measurements, the method of interpolation and more.…”

Analysis of Urban Green Spaces Based on Sentinel-2A: Case Studies from Slovakia

“…While we have found that it is very low in Žilina, the city is also less prone to experiencing heatwaves compared to the other two study areas-thanks to its basin location and higher elevation, the average high temperatures in summer are around 2 • C lower. Presented results of UGS assessment will serve as the input data for the definition of the local climate zones [39], and the MUKLIMO model [40,41] will be tested in the study areas. Further research oriented on the relationship between the spatial pattern of urban features and land surface temperature in the study areas will bring deeper insight into the effects of UGS on local urban microclimate.…”