／空飛ぶマンタ　2011

ある高度に巨大な膜状の構築物を作り出し、地球上の多数の人々の生活をより良くすることを目指す提案。
以下はあくまで仮説であるが、例えば毎年150万haが砂漠化するといわれるサハラ砂漠上空の対流圏に日射遮蔽の用で浮遊させ、直下の気温の下降や日較差の縮小、水分の蒸発量低下を促し、緑に覆われた本来のサハラを取り戻したり、農耕の可能性しいては食糧問題に言及できたりするかもしれない。あるいは北極近辺の成層圏に浮かべ、紫外線除去及びオゾン生成の基盤とする。それらを風の影響の少ない電離層に漂わせ、常に電力供給した状態で全世界を縦横無尽に移動させる。あるいは成層圏下部のジェット気流帯を縦断する帯状の膜にすると、大陸規模での熱融通の可能性もある。
今回はケーススタディとして、東京上空、高度１kmに夏期の日射遮蔽と太陽光発電を主な役割とする10km四方の膜を浮遊させる。
浮遊を実現するには風などの外乱への対策、面剛性や浮力の確保など種々の検討や実験が必要不可欠であるが、実現すれば少なくとも以下の効果が期待される。
膜の日射遮蔽率を0.5とした場合、8月中旬の建物表面温度は最も高温となる水平面において13℃、また地表面近傍の気温自体は10℃下がることを確認した。これは6月の快晴日（膜ナシ）よりも過ごしやすいと思われ、さらに日射の5割が直接人体及び衣服に当たらない快適感は木漏れ日のそれに等しいだろう。
また、冷房代は100km2 で年間92億円（試算、住宅のみ）の削減を期待できる。エアコンの有無だけで内部と外部の境界が定義されるではない、窓の自由な開閉を許容する初夏のよう な生活が真夏にも実現すれば、建築も少し変わるかもしれない。いわばこの膜は空調よりおおらかな環境設備であり、積乱雲より精緻な自然現象である。そしてこのまちは体育館より随分大きな内部であり、宇宙よりきわめて小さな外部のような場所になるのではないか。

「JA82」SUMMER, 2011 季刊　に掲載
Under 30 Architects exhibition 2011　に出展 記念シンポジウム当日の様子

Proposal that aims to produce a vast membrane-like constructs and to improve the lives of many people on the planet.
Without a fixed location, the membrane is studied to be a flexible solution to a number of problems of the world. For example, it could be suspended in the troposphere over the Sahara Desert, said to increase of 1.5 million ha every year. In this case the membrane could be suspended for solar radiation shielding, lowering the temperature immediately below, reducing the diurnal difference, helping regaining the original presence of vegetation and help in the production of agriculture or food. Another possibility could be for it to float in the stratosphere near the Arctic and use it as the basis for ultraviolet ray removal and ozone production.
It could be freed in the ionosphere with less influence of wind, floating in the whole world in a state of constant movement. Alternatively, the manta can be as a strip of film crossing the jet stream zone of the lower stratosphere, creating a thermal interchange on a continental scale.
As a case study, we will float the 10 km square membrane with the main role of solar radiation shielding and solar power generation in summer at 1 km altitude above the Tokyo case study.
Various investigations and experiments such as measures against disturbance such as wind, securing of surface rigidity and buoyancy are indispensable for achieving floating, but at least the following effects are expected if realized.
When the solar radiation shielding ratio of the film was 0.5, it was confirmed that the building surface temperature in the middle of August was 13 ° C. in the highest temperature, both horizontal surface and the air temperature in the vicinity of the ground surface decreased by 10 ° C. The feeling would be that of a sunny day in June where 50% of the solar radiation does not hit the human body and clothing directly, similarly to sunlight filtering through trees shadows.
In addition, it is expected that the cooling fee will be reduced by 9.2 billion yen (trial calculation, only for housing) for 100 km 2. The boundary between the inside and the outside is not defined only by the presence or absence of the air conditioner, if , for example, the interior climate condition changes into an early summer day which allows free opening and closing of windows, the construction may change a little. In other words, this membrane is more environmentally friendly than air conditioning, it is a more natural phenomenon than cumulonimbus. The result is a city with an interior much bigger than that of a gym and an exterior much smaller than outer space.

Published in 「JA82」SUMMER, 2011
Exhibited at Under 30 Architects exhibition 2011 記念シンポジウム当日の様子