تشير دراسة جديدة إلى أن المحيط المتجمد الشمالي تجاوز نقطة تحول حوالي عام 2009، حيث أدى فقدان الجليد البحري إلى انخفاض حاد في مستويات النترات في مياهه.
حلل باحثون من جامعة إدنبرة بيانات تمتد لأكثر من 20 عاماً من مضيق فرام. ووجدوا أن انخفاض مستويات النترات بدأ مع تراجع الجليد البحري بشكل سريع، مما عرض المياه الضحلة لمزيد من أشعة الشمس، وأدى إلى تسريع عملية تُعرف باسم نزع النترات القاعي التي تزيل هذا المغذي من مياه البحر.
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.
من إعداد الذكاء الاصطناعي
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.