Planktic foraminiferal distribution and stable isotope ratios of sediment core MSM05/5_712-1 from the Arctic Ocean

The Arctic is responding more rapidly to global warming than most other areas on our planet. Northward flowing Atlantic Water is the major means of heat advection towards the Arctic and strongly affects the sea ice distribution. Records of its natural variability are critical for the understanding of feedback mechanisms and the future of the Arctic climate system, but continuous historical records reach back only ~150 years. Here, we present a multidecadal scale record of ocean temperature variations during the last 2000 years, derived from marine sediments off Western Svalbard (79°N). We find that early-21st-century temperatures of Atlantic Water entering the Arctic Ocean are unprecedented over the past 2000 years and are presumably linked to the Arctic Amplification of global warming.

北极对全球变暖的响应速率远超地球上绝大多数其他区域。向北输送的北大西洋暖流水体是北极地区热平流的主要途径，并对海冰分布产生强烈影响。针对该水体自然变率的观测记录，对于理解气候反馈机制与北极气候系统的未来走向至关重要，但现存连续历史记录仅可追溯至约150年前。本研究基于斯瓦尔巴德群岛西侧（北纬79°）的海洋沉积物，重建了近2000年来的数十年尺度海洋温度变化序列。研究发现，进入北冰洋的北大西洋暖流水体在21世纪初的温度达到了近2000年来的空前水平，据推测其与全球变暖背景下的北极放大效应（Arctic Amplification）存在关联。