Airborne and Terrestrial Observations of the Thermal Environment of Urban Areas Surrounding a High-Rise Building during the Japanese Winter.

Haruki Oshio,Kan Chen,Takashi Asawa

doi:10.3390/s20020517

Abstract

We investigated the distribution of air temperature (Ta) and the factors affecting it in low-rise areas surrounding an isolated high-rise building during the Japanese winter. The study site was the central part of a regional city in Japan (36°5′ N, 140°12′ E), lying north-east of the Tokyo metropolitan area. The daytime surface temperature (Ts) in the shade is generally considered to be comparable to Ta; however, according to airborne remote sensing conducted in December 2009 where a multi-spectral scanner was installed on a fixed-wing aircraft, Ts for pavements in the shade of a high-rise building was significantly lower than Ta of sub-urban areas, indicating an influence of cold storage on Ts. Then, we conducted mobile observations using instruments (thermocouple, four component radiometer, and so on) installed on a bicycle in January 2016 to investigate the detailed distribution of Ta and the factors affecting it. The results showed the Ta over the pavements in the shade of the high-rise building was lower than the Ta of sunlit areas in the same urban area by −2 °C and lower than the Ta of sub-urban areas by −1–1.5 °C, although the advection effect was large due to strong winds around the building. In conclusion, a locally lower Ta compared to the surrounding areas can develop during the day in winter, even in spaces that are open to areas beyond the canopy.

Highlights

There has been a global increase in the construction of high-rise buildings throughout urbanized areas
According to remote sensing observations, the daytime Ts of pavements with a high heat capacity was significantly lower than Ta of the sub-urban area, indicating the influence of cold storage on Ts
L↑ were low throughout the daytime regarding the front of the high-rise building and the adjacent commercial building, and Ta was low, especially from morning to noon

Summary

Introduction

There has been a global increase in the construction of high-rise buildings throughout urbanized areas. The primary cause is considered to be interception of the incoming solar radiation on the inner part of the canopy by the buildings if the advection effect is small [3,4,5,6]. This is a similar situation to deep canyons (the height of the buildings is several times greater than the width of the road), where lower Ta inside the canyon compared to outside of the canyon have been observed [7,8,9].

Objectives

Results

Discussion

Conclusion