摘要
最后冰川的消失被巨大的冰表融化描绘,它导致平均海平面的上升类似于 120-140 m。至少三个主要 Melt-Water-Pulse (MWP ) 事件(19ka-MWP, MWP-1A 和 MWP-1B ) 为最后冰川的消失是可认识的,哪个持续从的 MWP-1A 事件类似于 14.2 到类似于 13.7 ka B.P 具有大多数意义。然而,精确预定和可争辩、争论的 MWP-1A 事件遗体的来源。融化流进诺思大西洋的最后冰川的消失的水,这长被要求了导致了减速或甚至一随后影响了全球气候的 thermohaline 发行量(THC ) 的 shutdown 变化。因此,这争论的焦点在建立在 MWP 事件和突然的气候变化之间的一种合理关系在于。这里,我们总结许多地质并且最后冰川的消失的模型结果,得出主要 MWP 事件没与严密 stadials 相应,也不总是发生在气候颠倒间隔以内的一个结论。最后冰川的消失的 MWP 事件在 THC 的紧张上有很弱的影响并且不能触发全球气候的倒塌。我们需要重新估计影响时间在全球气候系统上融化水可变性。
The last deglaciation is characterized by massive ice sheet melting, which results in an average sea-level rise of -120-140m. At least three major Melt-Water-Pulse (MWP) events (19ka-MWP, MWP-1A and MWP-1B) are recognizable for the last deglaciation, of which MWP-1A event lasting from -14.2 to -13.7 ka B.P. is of the most significance. However, the accurate timing and source of MWP-1A event remain debatable and controversial. It has long been postulated that meltwater of the last deglaciaUon pouring into the North Atlantic resulted in a slowdown or even a shutdown of the thermohaline circulation (THC) which subsequently affected the global climate change. Accordingly, the focus of this debate consists in establishing a reasonable relationship between MWP events and abrupt climate change. Here we summarize a variety of geological and model results for the last deglaciation, reaching a conclusion that the major MWP events did not correspond with the rigorous stadials, nor always happened within climate reversal intervals. MWP events of the last deglaciation had very weak influences on the intensity of the THC and were not able to trigger a collapse of the global climate. We need to reevaluate the influences of the temporal meltwater variability on the global climate system.
基金
the National Natural Science foundation of China (Grant Nos. 40476027, 40776028, 40621063 and 40331002)
the National Key Basic Research Specialized Foundation (Grant No. 2007CB815902)
the FANEDD (Grant No. 2005036) and Shanghai Rising-Star Program (Type A, Grant No. 06QA14052)
关键词
冰川退缩
MWP
温盐循环
气候剧变
deglaciation, Melt-Water-Pulse, thermohaline circulation, abrupt climate change