Distribution of Air Temperature in Tajimi City in Summer

To research the distribution of air temperature in the city of Tajimi, Gifu prefecture, a total of 15 thermometers were placed at the schools and parks in the city of Tajimi, and the city of Kasugai, Aichi prefecture in August 2010. From the distribution of monthly average air temperature, air temperature at the center of Tajimi city was higher than the suburbs. Also, the days of daily minimum air temperature more than or equal to 25°C and daily maximum air temperature more than or equal to 35°C at the elementary school near the center of Tajimi city was more than those at other schools. This tendency appeared more clearly on the days of daily minimum air temperature more than or equal to 25°C. Also, the air temperature near the center of the city was higher than that ofthe suburbs in the early morning. Thus, it was indicated that the air temperature was hard to decrease as the bottom of the basin. From these results, the influence of urbanization to the formation of the daily minimum temperature in Tajimi city was indicated

Observational Study and Numerical Prediction Experiments on Wet-Bulb Globe Temperature in Tajimi, Gifu Prefecture: Consideration of Uncertainty with a Physics Parameterization Scheme and Horizontal Resolution of the Weather Research and Forecasting Model

As part of research on the actual conditions of the thermal environment surrounding the city of Tajimi, Gifu prefecture, and the city of Kasugai, Aichi prefecture, the surface air temperature and wet-bulb globe temperature (WBGT) were investigated by observation at these locations on clear-sky days in August 2010. Numerical prediction experiments on the WBGT were performed to confirm the utility of the Weather Research and Forecasting (WRF) model. Sensitivity experiments utilizing physics parameterization schemes and horizontal resolution of the WRF model were conducted to confirm the predicted WBGT. The resultsshowed that the maximum sensitivity with the parameterization scheme was 8.4°C for the daytime average, and especially, the simple thermal diffusion surface (SLAB) scheme caused an over/estimation of 6.8°C. On the other hand, the maximum sensitivity with horizontal resolution was 0.5°C, which is much less than that with the parameterization scheme

Factors causing climatologically high temperatures in a hottest city in Japan: a multi-scale analysis of Tajimi

In this study, multi-scale climatological features of extreme high temperature (EHT) events in Tajimi, the hottest cities in Japan, were investigated using observational data collected by the Japan Meteorological Agency over the past 23 years, and original data observed by the authors over the last 3 years. Results revealed the background factors that lead to climatologically high temperatures in Tajimi: the occurrence of a characteristic pressure pattern called ‘whale’: the synoptic-scale factors, and the urbanization of Tajimi: the meso-γ-scale factors. In addition, the high temperatures measured in Tajimi are affected by the foehn-like westerly airflow coming from the mountains located in the northwest/west towards the Nobi Plain where Tajimi is located at the east end: the meso-β-scale factors, and the location of the Tajimi observation site, which is within an urbanized area where the highest temperatures tend to be observed: the micro-scale factors. In contrast, statistical analysis demonstrated that the small-scale basin effects and soil dryness around Tajimi were of lesser importance than aforementioned factors, in the occurrence of EHT events in Tajimi