Summer heat islands of Tokyo Metropolitan Area in connection with the occurrence of thermal lows and localized torrential rainfalls

2016 Fiscal Year Final Research Report

• Project/Area Number: 25242028
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Geography
• Research Institution: Teikyo University
• Principal Investigator: MIKAMI Takehiko 帝京大学, 文学部, 客員教授 (10114662)
• Co-Investigator(Kenkyū-buntansha): 森島 済 日本大学, 文理学部, 教授 (10239650) ; 日下 博幸 筑波大学, 生命環境科学研究科(系), 准教授 (10371478) ; 高橋 日出男 首都大学東京, 都市環境科学研究科, 教授 (40202155) ; 赤坂 郁美 専修大学, 文学部, 准教授 (40574140) ; 平野 淳平 帝京大学, 文学部, 講師 (80567503) ; 佐藤 英人 高崎経済大学, 地域政策学部, 准教授 (00396798)
• Co-Investigator(Renkei-kenkyūsha): SAKAI Shin-ichi 東京大学, 地震研究所, 准教授 (00251455)
• Research Collaborator: YAMATO Hiroaki
• Project Period (FY): 2013-10-21 – 2017-03-31
• Keywords: ヒートアイランド / 東京 / 局地的豪雨 / 気温 / 観測

Outline of Final Research Achievements

We made an attempt at clarifying the relationship between thermal lows and localized torrential rainfalls in Tokyo Metropolitan Area based on the high-density temperature and air pressure observation system which we developed since 2006. As a result of Principal Component Analysis for the summer temperature and pressure data matrices in Kanto region, typical spatial patterns which related to the sea-land breeze circulations, urban heat islands and north-easterlies were detected.
A case study on the localized torrential rainfall indicated that lowering and increasing trend of air pressures around heavy rainfall area occurred, where high temperatures and moist air penetration from sea-breeze were observed. Finally, “Weather Research & Forecasting ( WRF )” model were applied to detect the urban effect due to heat islands. The results show increasing rainfall in urban area during the night in summer.

Free Research Field

気候学