著者

Kyosuke Kawano Ryoko Oda Atsushi Inagaki Makoto Nakayoshi

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.16, pp.192-197, 2020 (Released:2020-10-29)

参考文献数

23

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The thermal stress along a marathon course in Tokyo is evaluated using a radiation balance model. The wet-bulb globe temperatures (WBGTs) for runners and spectators are calculated based on the surrounding building and tree geometries using the Solar LongWave Environmental Irradiance Geometry model. Analysis is conducted in terms of summer days in August 2018, which was during the hottest summer in the past 5 years. The WBGT classification for runners along the outward leg (until around 14 km) reaches the “Warning” level (WBGT = 26.5°C) despite of the many shadows on the street in the early morning (until 0645 JST). The WBGT increases around the Imperial Palace because the road has a sky view factor of over 95%, and no obstacles to make shadows on the street at around 0750 JST. The WBGT classification for runners reaches the level of “Severe warning”. For spectators, the difference of average WBGT from the runners are about 0.1°C although the difference could be significant locally due to partial shading on a road side.

著者

Kyosuke Kawano Ryoko Oda Atsushi Inagaki Makoto Nakayoshi

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

pp.2020-033, (Released:2020-09-10)

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The thermal stress along a marathon course in Tokyo is evaluated using a radiation balance model. The wet-bulb globe temperatures (WBGTs) for runners and spectators are calculated based on the surrounding building and tree geometries using the Solar LongWave Environmental Irradiance Geometry model. Analysis is conducted in terms of summer days in August 2018, which was during the hottest summer in the past 5 years. The WBGT classification for runners along the outward leg (until around 14 km) reaches the “Warning” level (WBGT = 26.5°C) despite of the many shadows on the street in the early morning (until 0645 JST). The WBGT increases around the Imperial Palace because the road has a sky view factor of over 95%, and no obstacles to make shadows on the street at around 0750 JST. The WBGT classification for runners reaches the level of “Severe warning.” For spectators, the difference of average WBGT from the runners are about 0.1°C although the difference could be significant locally due to partial shading on a road side.

著者

Hirofumi SUGAWARA Ryoko ODA Naoko SEINO

出版者

Meteorological Society of Japan

雑誌

Journal of the Meteorological Society of Japan. Ser. II (ISSN:00261165)

巻号頁・発行日

pp.2018-010, (Released:2017-12-21)

被引用文献数

6

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Does the cities enhance precipitation? It is an unsettled question and the comprehensive answer has not been archived for it. This study focuses on the urban heat excess and evaluates its influence on atmospheric instability which is the background condition for the convective precipitation. A simple approach was developed that involved calculating the daytime evolution of the mixed layer over homogeneous ground surface. Calculations were based on the ensemble average of observations. The convective available potential energy (CAPE) was evaluated for both urban and rural land cover. Urban heat excess, which was 200 W m-2 higher in the urban than rural area, increased CAPE by 75 % comparing to the rural CAPE of 513 J kg-1. Results show that cities could cause favorable stratification of the atmosphere for convective precipitation.