Possible solar origin of the 1,470-year glacial climate cycle demonstrated in a coupled model
Possible solar origin of the 1,470-year glacial climate cycle demonstrated in a coupled model
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DOI：
10.1038/nature04121
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发表时间：
2005-11-10
期刊：
影响因子：
64.8
通讯作者：
Kromer, B
中科院分区：
文献类型：
--
作者：
Braun, H;Christl, M;Kromer, B
北大西洋区域的许多古气候记录显示了一种快速气候振荡的模式，即所谓的丹斯加德·奥施格事件，其准周期类似于晚冰期(1-6年)的1,470年。人们提出了各种假设来解释这种快速的温度变化，包括气候系统的内部振荡和外部强迫，可能来自太阳[7]。但是，尽管类似于87年和类似于210年的明显的太阳周期是众所周知的(8-12年)，但类似于1470年的太阳周期还没有被检测到(8)。在这里，我们展示了一个具有冰川气候条件的中等复杂气候模式，模拟了类似于Dansgaard-Oeschger事件的快速气候变化，当被周期性的淡水输入北大西洋时，间隔为1,470年，周期为87年和210年。我们将1470年的强健响应时间归因于两个较短的周期、强烈的非线性动力学和热盐环流的长特征时间尺度的叠加。对于全新世的情况，类似的事件不会发生。我们的结论是，尽管没有1470年的太阳周期，但冰川1470年的气候周期可能是由太阳强迫引发的。
Many palaeoclimate records from the North Atlantic region show a pattern of rapid climate oscillations, the so-called Dansgaard Oeschger events, with a quasi-periodicity of similar to 1,470 years for the late glacial period(1-6). Various hypotheses have been suggested to explain these rapid temperature shifts, including internal oscillations in the climate system and external forcing, possibly from the Sun(7). But whereas pronounced solar cycles of similar to 87 and similar to 210 years are well known(8-12), a similar to 1,470-year solar cycle has not been detected(8). Here we show that an intermediate-complexity climate model with glacial climate conditions simulates rapid climate shifts similar to the Dansgaard - Oeschger events with a spacing of 1,470 years when forced by periodic freshwater input into the North Atlantic Ocean in cycles of, 87 and, 210 years. We attribute the robust 1,470-year response time to the superposition of the two shorter cycles, together with strongly nonlinear dynamics and the long characteristic timescale of the thermohaline circulation. For Holocene conditions, similar events do not occur. We conclude that the glacial 1,470-year climate cycles could have been triggered by solar forcing despite the absence of a 1,470-year solar cycle.