The Interaction between Nocturnal Heat Islands and Mountain Breezes in Several Cities located on a Valley Mouth in Japan

• Sato, Norihito

抄録

type:Other

In this paper the author sought to clarify the interaction between the nocturnal heat island phenomenon and the mountain breezes in some cities located on a valley mouth under the mete orological high pressure conditions. As subjects of this study, the author selected three cities as the field of investigation : Hachioji, Ome, and Nikko-Imaichi. All these cities are situated on the valley mouth of a river in the Kanto District in Japan (Figs. 1, 2 & 3). The results of this study are summarized as follows: 1. In these cities the nocturnal heat island phenomenon can be recognized clearly and mountain breezes blow on the warm air over the urban area from the upper part of each river. Under certain meteorological conditions, the mountain breezes blow away the warm air over the city area to a leeward direction. 2. In Hachioji City the heat island intensity is a little weak in comparison with the city's popu lation size. Perhaps because there is a basin around the Hachioji urban district, from a geomorphological viewpoint, a cold-air lake is formed during the night. Specifically, after sunset the air near the ground is cooled gradually by radiation from the earth while the air in the city is pooled from the surrounding area. These factors prevent the heat island phenomenon from developing a clear form. 3. The vertical structure of air over these cities is comprises three different air-layers. The bottommost air-layer is equal to the ground inversion layer, which is a stable layer that also occurs slightly in suburbs. Above this stable layer, a mountain breeze with a comparatively low temperature blows after sunset. Furthermore, above the layer of mountain breeze, wind circulated via land and sea on a wider scale blows as the prevailing wind. From these facts, a figure depicting the vertical structure of air over these cities located on a valley mouth is approximately that shown in Fig. 22.

収録刊行物

• Japanese progress in climatology

  Japanese progress in climatology 2013 65-76, 2013-12

  Japan Climatology Seminar

キーワード

• ground inversion
• valley mouth settlement
• heat island phenomenon
• mountain breeze

詳細情報

• CRID: 1050298919736805120
• NII論文ID: 120005620075
• NII書誌ID: AA00249627
• ISSN: 00753467
• Web Site: http://hdl.handle.net/10114/10933
• 本文言語コード: en
• 資料種別: article
• データソース種別:
  • IRDB
  • CiNii Articles