18 0 0 0 OA 北極海における海氷激減メカニズムについての考察
- 著者
- 島田 浩二
- 出版者
- 公益社団法人 東京地学協会
- 雑誌
- 地学雑誌 (ISSN:0022135X)
- 巻号頁・発行日
- vol.119, no.3, pp.451-465, 2010-06-25 (Released:2010-08-30)
- 参考文献数
- 24
- 被引用文献数
- 1 1
The rate of recent sea ice reduction in the Arctic Ocean exceeds that of global warming. The pattern of sea ice reduction accompanies discontinuous changes. This implies that the Arctic climate system is not only influenced by global warming, but also involves significant positive feedback mechanisms that accelerate the reduction of sea ice. Changes of sea ice area in the Arctic Ocean do not show uniform reductions in both space and time. In the present study, we investigate sea ice reduction in distinct regions and time frames, taking into consideration preconditions for the occurrence of tipping points. The initiation of a positive feedback system is found in strengthening ocean and ice circulations since the late 1990s. The activation of both sea ice and ocean circulation caused ocean warming. This contributed to less formation and growth of sea ice in the Pacific Sector. Consequently, ice reduction actually occurred due to an imbalance between ice melt and formation. The sustaining of strong circulations was a precondition leading to a huge anomalous sea ice reduction in 2007 with a zonal asymmetric distribution. The resultant zonal asymmetry establishes a new atmospheric pattern (dipole pattern) associated with southerly winds in the Pacific sector of the Arctic Ocean. Now, the Arctic climate is governed by a strong coupling system linking ocean, ice, and atmosphere. Multi-disciplinary studies are now required to understand the catastrophic Arctic changes and the fate of the Arctic and global climate.
1 0 0 0 OA 自閉症スペクトラム障害の早期診断のためのオミックス解析と発達コホート研究
自閉スペクトラム症(ASD)の発症リスク因子である環境ストレスとしてのミクログリア活性化分子ネットワークに着目し、ASDのバイオマーカー候補としてmiRNA(micro-RNA)解析を行った。福井県A町で出生した子の発達に関する前向きコホート調査参加者の母子に対し、視線計測検出装置による社会性の評価を行った。その結果、母のメンタルヘルスは乳児期における子の社会性発達へ影響することが示唆された。また、月齢により異なる側面の社会性が発達するが、その発達の程度はOXTR遺伝子多型によって異なる可能性が示唆された。本成果は、ASDの病態解明を目指した臨床応用への足掛かりになりうる。