Abrupt climate change: causal constraints provided by the paleoclimate record
Abrupt climate change: causal constraints provided by the paleoclimate record
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DOI：
10.1016/s0012-8252(00)00019-2
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发表时间：
2000-08-01
影响因子：
12.1
通讯作者：
Broecker, WS
中科院分区：
文献类型：
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作者：
Broecker, WS
第四纪晚期气候变化所涉及的物理学的重要方面，我们还没有弄清楚。古气候记录详细地记录了这些变化是巨大的，在许多情况下是突然发生的。全球气候系统的每一个要素都参与其中。虽然一个案件可以说，这些重组海洋的温盐环流作为触发这些跳跃，还没有人能够确切地阐明它是如何，这些重组是能够诱导如此大的变化，在大气运作的方式，在这篇评论中，我指出什么对我来说是由保存在冰和沉积物中的记录放置的关键限制。这些变化的时间表明，它们是由与地球轨道要素的周期性有关的季节性变化和北方大西洋沉积物上奇怪的1500年周期决定的。但是，由于这些起搏器天生就很弱，为了让它们产生我们在记录中看到的东西，系统中必须存在强大的和可能的非线性反馈。我希望通过汇集这些信息，我将为能够照亮这些反馈的物理场景的创造性思维提供动力。这不仅是了解我们过去的关键一步，而且也是我们正确评估持续温室气体积累可能后果的必要一步。(C)2000 Elsevier Science B.V.保留所有权利。
Important aspects of the physics involved in the climate changes of late Quaternary time elude us. The paleoclimatic record documents in detail that these changes were vast and in many cases happened abruptly. Every element of the global climate system was involved. While a case can be made that these reorganizations of the ocean's thermohaline circulation acted as the trigger for these jumps, no one has as yet been able to articulate exactly how it is that these reorganizations are capable of inducing such large changes in the way in which the atmosphere operates.In this review, I point out what to me are the key constraints placed by the records kept in ice and in sediments. The timing of these changes suggests that they have been paced by seasonality changes related to periodicities in the Earth's orbital elements and by a curious 1500-year cycle imprinted on sediments in the northern Atlantic. But as these pacemakers are inherently weak, in order for them to generate what we see in the record, there must exist powerful and likely nonlinear feedbacks in the system. It is my hope that by bringing together this information, I will provide an impetus for creative thinking with regard to physical scenarios capable of illuminating these feedbacks. Not only is this the crucial step in understanding our past, but it is also a necessary step if we are to properly evaluate the possible consequences of the ongoing greenhouse gas buildup. (C) 2000 Elsevier Science B.V. All rights reserved.