Long-term measurements for investigating the vertical thermodynamics of an urban boundary layer with high-rise buildings

•Temperature inversion layer and warm zone in Taipei UBL change by season.•Taipei urban boundary layer characteristics differ from standard weather model.•Differences in UBL mixing layer height and roughness sublayer compared to models.•Improvements in UBL heat transfer necessary for accurate climate and weather models.•Potential implications for improved air pollution and climate meteorology modeling. Long-term observations investigating the urban boundary layer including high-rising buildings remain inadequate. In this study, we installed two meteorological stations and utilized three other stations at five different heights in the city of Taipei, Taiwan to construct a long-term virtual potential temperature profile to investigate the thermodynamics of the urban boundary layer. Measurements using radio sounding and LIDAR validated the feasibility of this approach. Measurements from sites which are close to each other in distance but at different heights were compared to deduce historical virtual potential temperature profiles. According to changes in annual measurements, the temperature inversion layer can decrease to approximately 350 m depending on the time of year, while the warm zone near the surface during the daytime becomes volatile, and can grow up to heights more than 200 m. Importantly, our study shows that the structure of the convective urban boundary layer in Taipei is markedly different compared to previous studies, with our simulations versus a Weather Research and Forecasting model showing differences both in the height of the mixing layer and the roughness sublayer of the urban boundary layer. Improvements in heat transfer in the urban boundary layer scheme are necessary for the accuracy of current climate and weather models.