Generation and analysis of typical meteorological years for future weather and detection of heatwaves

With the increase of mean and extreme ambient temperatures, it is necessary not only to use future typical weather conditions but also future heatwaves for building simulation of energy use and indoor environmental conditions. In this study, a methodology suggested by Weather Data Task Force, IEA EBC Annex 80 was used to generate future weather files and detect heatwaves in the future periods for Copenhagen. The weather datasets for three periods (current, mid-term future and long-term future) from the European Coordinated Regional Downscaling Experiment (EURO-CORDEX) were bias-adjusted by the historical observation data. Two types of future weather datasets are produced: typical meteorological years (TMYs) and heatwave events (HWEs), which can be used to fully assess the resilience of buildings to overheating in the current and future climate conditions. The TMY data generated by the newly proposed method was compared with the one generated by the commercial weather generator Meteonorm. The result shows that the new method has a relatively conservative prediction of outdoor dry-bulb temperatures in the long-term future. Four definitions were used to detect HWEs in three different periods for Copenhagen, including the new definition with/without thermal adaptation and two Danish definitions. The HWEs will not be more frequent but longer in the end of this century when considering thermal adaptation. In the future, the temperature threshold calculated by daily average temperature is recommended to be used for detecting heatwaves, which can well consider the impact of global temperature rising. How thermal comfort and heat stress is defined and applied to buildings have important implications for the definition and analysis of heatwaves. Therefore, the change of the adaptability of people and buildings to heat stress with the rise of the overall temperature should be considered when detecting heatwave.