地球の気候を調節している大西洋の主要な海流システムが、20年近くにわたり減速していることが分かった。新たな研究により、北大西洋の広範囲にわたるこの減衰の直接的な証拠が示された。
マイアミ大学ローゼンスティール海洋大気地球科学大学院の研究チームがこの研究を主導した。研究チームは、熱帯から中緯度にかけて設置された4つの海底モニタリング装置から得られたデータを分析。これらの機器は、水深1,000メートル以深の深海流を追跡するため、圧力、水温、海流を測定した。
A new modelling study indicates that a weakening Atlantic Meridional Overturning Circulation is causing the Gulf Stream to drift northwards, with satellite data showing a 50-kilometre shift over 30 years. Researchers suggest this gradual change could precede an abrupt move serving as an early warning for a potential AMOC collapse. Such a collapse might lead to drastic cooling in Europe, though timelines remain uncertain.
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New studies indicate that stronger winds and warming deep ocean water have triggered a sharp decline in Antarctic sea ice since 2016. Previously expanding, the ice reached a record high in 2014 before plummeting to record lows. Researchers link this shift to wind-driven upwelling of circumpolar deep water.
New data from the European Space Agency's Swarm satellites reveal that the South Atlantic Anomaly, a weak spot in Earth's magnetic field, has grown by nearly half the size of continental Europe since 2014. A region southwest of Africa is weakening even faster in recent years. This expansion highlights unusual activity in Earth's molten outer core.
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Researchers at The Hong Kong Polytechnic University have analyzed 30 years of data to show that global sea levels have risen by about 90 millimeters since 1993, with melting land ice now driving most of the increase. The study, using satellite laser ranging, indicates an average rise of 3.3 millimeters per year, a rate that is speeding up. Ocean mass from ice melt accounts for over 60 percent of the rise since 2005.