Observation of the "Cool Island Effect" in the Imperial Gardens

During this summer, the Ministry of the Environment made detailed temperature observations in and around the Imperial Gardens in order to verify the "cool island effect" and the "seeping-out phenomena of cooled air" from the Gardens. As a result, it was found that the average temperature of August, 2007 in the Imperial Gardens, which was 28.0 degrees C, was 1.8 degrees lower than that of the surrounding built-up areas. Additionally, we detected advection of cooled air from the Imperial gardens to neighboring built-up areas within a distance of 350 meters during the daytime. It is also noteworthy that "cooled air seeping-out phenomena" were detected for the first time around the Imperial Gardens from mid-night to early morning under calm weather conditions, during which the cooled air was seeping out to the surrounding built-up areas within a distance of 250 meters.

The meteorological observations and the data analysis were conducted in cooperation with the research team headed by Professor Takehiko Mikami of Tokyo Metropolitan University. For the observations, we received special permission from the Imperial Household Agency.

Submit to:
Office of Odor, Noise and Vibration, Air Quality Management Division, the Ministry of the Environment
(Mail) No.5 Godochosha Building, 1-2-2 Kasumigaseki, Chiyoda-ku, Tokyo, 100-8975
(FAX) 3-3593-1049
(e-mail) heat@env.go.jp

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