تباطأ نظام تيار رئيسي في المحيط الأطلسي يعمل على تنظيم المناخ العالمي لما يقرب من 20 عاماً. وتقدم أبحاث جديدة أدلة مباشرة على هذا التراجع عبر مساحة واسعة من شمال المحيط الأطلسي.
قاد علماء من كلية روزنستيل لعلوم البحار والغلاف الجوي والأرض بجامعة ميامي هذه الدراسة. وقام الباحثون بتحليل بيانات من أربع مصفوفات مراقبة في قاع البحر تمتد من المناطق الاستوائية إلى خطوط العرض الوسطى. وقاست هذه الأجهزة الضغط ودرجة الحرارة والتيارات لتتبع تدفقات أعماق المحيط تحت مستوى 1000 متر.
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.
من إعداد الذكاء الاصطناعي
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.
من إعداد الذكاء الاصطناعي
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.