全文: "南極振動"
10件中 1-10の結果を表示しています
  • 立花 義裕, 井上 裕介, 本田 明治, 中村 哲, 山崎 孝治, 小寺 邦彦
    2016年 2016 巻
    発行日: 2016年
    公開日: 2017/02/18
    会議録・要旨集 フリー
  • 山崎 孝治
    2008年 117 巻 6 号 1051-1062
    発行日: 2008/12/25
    公開日: 2010/04/26
    ジャーナル フリー
     The Arctic Oscillation (AO; Northern hemisphere annular mode), which is the most dominant mode of climate variability in the Northern extratropics, is reviewed. The AO is a seesaw pattern between the Arctic region and the mid-latitude regions. It is an atmospheric internal mode caused by interaction between mean flows and eddies. In winter, it extends to the stratosphere, and the tropospheric AO interacts with the stratospheric AO. Since the mid-20th century, the AO has shown an increasing trend in winter and summer. Climate models predict a future positive trend due to global warming. Recent sea ice loss in the Arctic Ocean is also discussed. The decline of the Arctic sea ice cover in late summer has accelerated recently and a record-low ice cover was observed in September 2007. The rate of decrease is much faster than climate model predictions, and it might pass a tipping point.
  • 森岡 優志
    2020年 29 巻 1 号 1-17
    発行日: 2020/01/15
    公開日: 2020/02/21
    ジャーナル フリー


  • 泉宮 尊司, 小関 達郎
    2010年 66 巻 1 号 1251-1255
    発行日: 2010年
    公開日: 2010/11/09
    ジャーナル フリー
    Climate variabilities in characterictics of typhoon, annual precipitation and SST are investigated in connection with the indecies of atomospher- ocean interaction such as MEI, PDO, NAO and AO. Spectra of annual time serries of the climate indecies were analyed to find a relationship between the climate change and the indecies of ocean-atmosphere interaction. A five-year variation in an annual mean minimum pressure of typhoon is found to have the same period of MEI and about one year time lag. The other climate indecies are found to change with the indecies of large-scale atmosphere-ocean interaction, such as MEI and PDO. The activity of typhoon and climate valiations are estimated employing linear system analysis with the impulse response functions and are compared with the measured climate data.
  • 伊藤 公紀
    2005年 53 巻 6 号 342-345
    発行日: 2005/06/20
    公開日: 2017/07/11
    解説誌・一般情報誌 フリー
  • 伊藤 進一, 船本 鉄一郎, 志田 修, 上村 泰洋, 髙橋 素光, 白井 厚太朗, 樋口 富彦, 小松 幸生, 横井 孝暁, 坂本 達也, 郭 晨颖, 石村 豊穂
    2018年 27 巻 1 号 59-73
    発行日: 2018/01/15
    公開日: 2018/03/13
    ジャーナル フリー


  • 佐々木 克徳
    2016年 25 巻 1 号 1-16
    発行日: 2016/01/15
    公開日: 2018/10/25
    ジャーナル フリー

    地球の気候システムにおいて海洋循環の西岸境界流およびその続流は大量の熱を熱帯域から極域へと運び,大気へ放出するなど重要な役割を果たしている。本稿ではその西岸境界流の中で黒潮続流域,メキシコ湾流域,および南太平洋亜熱帯循環域における十年スケール変動とそのメカニズムについての研究成果を紹介する。黒潮続流の十年スケール変動のメカニズムとして,ジェットに沿って西方伝播するjet-trapped ロスビー波を提案し,このロスビー波により西方伝播するシグナルの速度や十年スケール変動の空間構造,振幅が良く説明されることを示す。またこのjet-trappedロスビー波は,黒潮続流の流速や中規模渦活動,日本沿岸の水位変動にも大きく影響する。同様にメキシコ湾流の変動にもjet-trappedロスビー波が重要である。一方,南太平洋亜熱帯循環の強さも顕著な十年スケール変動を示し,エルニーニョの十年スケール変動に伴う風の変動によって励起される線形長波ロスビー波で良く説明される。

  • ―日本海洋学会将来構想委員会物理サブグループの議論から―
    岡 英太郎, 磯辺 篤彦, 市川 香, 升本 順夫, 須賀 利雄, 川合 義美, 大島 慶一郎, 島田 浩二, 羽角 博康, 見延 庄士郎, 早稲田 卓爾, 岩坂 直人, 河宮 未知生, 伊藤 幸彦, 久保田 雅久, 中野 俊也, 日比谷 紀之, 寄高 博行
    2013年 22 巻 6 号 191-218
    発行日: 2013/11/15
    公開日: 2019/03/22
    ジャーナル フリー


  • ―現代および第四紀後期の海氷分布,南極前線,南極周極流の移動と気候変動のリンケージ―
    池原 実
    2012年 121 巻 3 号 518-535
    発行日: 2012/06/25
    公開日: 2012/07/09
    ジャーナル フリー
     The Southern Ocean plays an important role in the global climate system both at present and in the geologic past. To resolve the causes and processes of atmospheric CO2 change, it is important to understand the mechanisms and processes of sub-systems in the Antarctic Cryosphere such as change of biological productivity, sea-surface temperature, surface water frontal system, sea ice distribution, and the Antarctic Ice Sheet during the glacial-interglacial climate cycle. A large number of float observations made recently suggest that mid-depth Southern Ocean temperatures rose 0.17°C between the 1950s and 1980s. The Southern Ocean is warming faster than the global oceans, and this is concentrated within the Antarctic Circumpolar Current (ACC). Warming is consistent with a poleward shift of the ACC, probably driven by long-term poleward shifts in the winds of the region, as represented by the southern annular mode. Changes to the extent of Antarctic sea ice are difficult to quantify for the pre-satellite observation era. However, a substantially larger set of proxy records based on whaling positions indicates that a larger southward shift of the summer sea ice edge occurred between the mid-1950s and early 1970s. In the glacial to interglacial cycle, ice-rafted debris (IRD) is an important proxy for reconstructing past iceberg discharges and sea ice expansions. However, it is necessary to specify the origin of IRD in the Southern Ocean, because IRD deposition on the pelagic seafloor is controlled not only by the dynamics of the Antarctic ice sheet but also by surface water conditions such as sea-surface temperature and oceanic front migrations. For example, several layers rich in volcanic tephra were deposited in the eastern Atlantic sector of the Southern Ocean. Deposition of the tephra-rich IRD layers was controlled by changes in sea-surface temperature and sea ice conditions in the Polar Frontal Zone of the South Atlantic, rather than Antarctic ice sheet dynamics. Thus, IRD deposition is a signal of the expansion of sea ice in the South Atlantic. According to IRD records, it seems that sea ice expansion events occurred suddenly in the Atlantic sector of the Southern Ocean during the last glacial period.
  • 山川 修治
    2005年 114 巻 3 号 460-484
    発行日: 2005/12/25
    公開日: 2009/11/12
    ジャーナル フリー
    Research on factors of climate variations on a seasonal to multi-decadal timescale is surveyed. However, it is difficult to fully cover wide-ranging research on climate systems including the latest results. This paper focuses on phenomena such as QBO that interact with the other factors. Oceans, which have a close relationship with climate change, are considered. Although there is overlapping with dissertations in another chapter, the main contents are as follows 1) ENSO is a quasi-periodic air-sea interaction, which has been studied closely. If evolvement of ENSO is predicted, it will make seasonal weather forecasts more precise. 2) The effects of stratospheric QBO on climate systems in the troposphere might have been exercised as grave cool damage that occurs in summers when QBO was in the W-phase, and some correlations have been found. QBO probably holds a significant key explaining climate variations. Therefore, elucidation of the QBO mechanism that influences the troposphere can be expected. 3) The relationship between solar activities and climate remains obscure. However, some influences of solar activities on the tropospheric circulation have been felt through sea surface temperature or interaction with stratospheric QBO. 4) In the air-sea interaction the ocean responds to solar radiation more slowly than the atmosphere, so the ocean seems to play a dominant role in long-lived teleconnections such as PDO. In addition, regime shifts of oceans sometimes have major effects on climate. We cannot discuss climate change without referring to oceans. 5) Global warming is in progress. As a result, shifts in general circulation might lead to abnormal weather, which means increased danger of frequent developments of the Okhotsk high, which is responsible for cool summer damage. 6) It is important to evaluate which factors contribute greatly to climate change. Understanding the mechanisms of weather fluctuations ranging from a few months to several years is a pressing matter to prevent recurrence of meteorological disasters.