School of Archaeology, Geography and Environmental Science, Reading University, Whiteknights, Reading, RG6 6AH, UK.
Sci Rep. 2022 Jun 22;12(1):10542. doi: 10.1038/s41598-022-14684-y.
Abrupt events are a feature of many palaeoclimate records during the Holocene. The best example is the 8.2 ka event, which was triggered by a release of meltwater into the Labrador Sea and resulted in a weakening of poleward heat transport in the North Atlantic. We use an objective method to identify rapid climate events in globally distributed speleothem oxygen isotope records during the Holocene. We show that the 8.2 ka event can be identified in >70% of the speleothem records and is the most coherent signal of abrupt climate change during the last 12,000 years. The isotopic changes during the event are regionally homogenous: positive oxygen isotope anomalies are observed across Asia and negative anomalies are seen across Europe, the Mediterranean, South America and southern Africa. The magnitude of the isotopic excursions in Europe and Asia are statistically indistinguishable. There is no significant difference in the duration and timing of the 8.2 ka event between regions, or between the speleothem records and Greenland ice core records. Our study supports a rapid and global climate response to the 8.2 ka freshwater pulse into the North Atlantic, likely transmitted globally via atmospheric teleconnections.
在全新世期间，许多古气候记录都有突然事件这一特征。最好的例子是 8.2ka 事件，该事件是由拉布拉多海的融水释放引发的，导致北大西洋的极地向热量输送减弱。我们使用一种客观的方法来识别全新世期间全球分布的石笋氧同位素记录中的快速气候变化事件。我们表明，8.2ka 事件可以在超过 70%的石笋记录中识别出来，并且是过去 12000 年来最一致的突发气候变化信号。该事件期间的同位素变化在区域上是同质的：在亚洲各地观察到正的氧同位素异常，而在欧洲、地中海、南美洲和南部非洲则观察到负异常。欧洲和亚洲的同位素偏移幅度在统计学上是不可区分的。各个地区之间、石笋记录和格陵兰冰芯记录之间，8.2ka 事件的持续时间和时间都没有显著差异。我们的研究支持了对北大西洋 8.2ka 淡水脉冲的快速和全球气候响应，可能通过大气遥相关在全球范围内传播。
