新しい研究によると、北極海は2009年頃に臨界点を超えたことが明らかになりました。海氷の減少により、海水の硝酸塩レベルが急激に低下しています。
エディンバラ大学の研究チームがフラム海峡で収集された20年以上にわたるデータを分析した結果、海氷が急速に後退し始めた時期と硝酸塩の減少が始まった時期が一致していることがわかりました。海氷の減少によって浅瀬に日光がより多く当たるようになり、海水から栄養素を取り除く「底生脱窒」と呼ばれるプロセスが加速したことが原因です。
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.
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Scientists using deep-diving Argo floats have pinpointed the reason behind Antarctica's dramatic sea ice contraction starting in 2016. The decline stems from a violent release of pent-up heat from ocean depths, triggered by shifting winds and salinity changes. This discovery highlights the ocean's key role in sea ice variability.
A new study shows that channels beneath Antarctic ice shelves can trap warm ocean water and accelerate melting from below. Researchers focused on the Fimbulisen Ice Shelf in East Antarctica and found that this process may make even cold regions more vulnerable. The findings suggest current climate models could underestimate future sea level rise.
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Researchers at the University of Rochester have identified a key mechanism for methane production in the open ocean, driven by phosphate scarcity. The discovery, published in Proceedings of the National Academy of Sciences, suggests warming oceans could boost these emissions, creating a potential climate feedback loop. This resolves a long-standing puzzle about methane in oxygen-rich surface waters.