Questioning the Influence of Sunspots on Amazon Hydrology: Even a Broken Clock Tells the Right Time Twice a Day
Questioning the Influence of Sunspots on Amazon Hydrology: Even a Broken Clock Tells the Right Time Twice a Day
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DOI：
10.1002/2017gl076889
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发表时间：
2018-02-16
影响因子：
5.2
通讯作者：
Brienen, R. J. W.
中科院分区：
文献类型：
--
作者：
Baker, J. C. A.;Gloor, M.;Brienen, R. J. W.
最近的一篇文章提出，太阳黑子驱动了亚马逊河流量的十年变化。这一结论是基于一种新的时间序列分解方法，用于提取亚马逊河记录的十年信号。我们已经扩展了这种分析的时间，使用一个新的水文代理记录的树轮氧同位素（三角洲O-18（TR））。与Antico和托雷斯的发现一致，我们发现太阳黑子与1903年至2012年的十年三角洲O-18（TR）周期之间存在正相关性（r = 0.60，p < 0.001）。然而，这种关系并没有持续到前一个世纪，甚至变成了弱负（r =-0.30，p = 0.11，1799-1902）。这一结果使人们对太阳黑子影响亚马逊河水文的机制产生了相当大的怀疑。简明语言摘要在最近的一篇论文中，研究人员发现了亚马逊河中流动的水量与太阳活动变化之间的可能联系，这一联系是通过太阳黑子的数量来衡量的。然而，这种关系的确切细节以及它可能如何运作还没有完全了解，分析只涵盖了20世纪。亚马逊树的年轮（在许多温带和热带树木的木材中可见的年度生长带）已被证明记录了流域降雨量（以及亚马逊河流量）的信息，在它们形成的那一年，因此提供了一种将水文记录追溯到过去的方法。在这项研究中，我们使用了来自厄瓜多尔的一个新的树木年轮数据集来测试200年来太阳黑子和亚马逊水循环之间的联系。我们表明，太阳黑子和亚马逊河流量之间的关系并不是随着时间的推移而恒定的，甚至可能是偶然出现的，就像一个坏了的时钟的指针每天指向正确的时间两次。这项工作强调了代理气候数据集有时比单独的仪器气候数据提供更多的见解。
It was suggested in a recent article that sunspots drive decadal variation in Amazon River flow. This conclusion was based on a novel time series decomposition method used to extract a decadal signal from the Amazon River record. We have extended this analysis back in time, using a new hydrological proxy record of tree ring oxygen isotopes (delta O-18(TR)). Consistent with the findings of Antico and Torres, we find a positive correlation between sunspots and the decadal delta O-18(TR) cycle from 1903 to 2012 (r = 0.60, p < 0.001). However, the relationship does not persist into the preceding century and even becomes weakly negative (r = -0.30, p = 0.11, 1799-1902). This result casts considerable doubt over the mechanism by which sunspots are purported to influence Amazon hydrology.Plain Language Summary In a recent paper, researchers identified a possible connection between the amount of water flowing in the Amazon River and changes in solar activity, measured by number of sunspots. However, the precise details of this relationship and how it might work were not fully understood, and the analysis only covered the 20th century. Amazon tree rings (the annual growth bands visible in the wood of many temperate and tropical trees) have been shown to record information about basin rainfall (and hence Amazon River flow), in the year of their formation, and therefore offer a way to extend the hydrological record back in time. In this study, we used a new tree ring data set from Ecuador to test the link between sunspots and the Amazon water cycle over a 200 year period. We show that the relationship between sunspots and Amazon River flow is not constant over time and suggest it might even arise by chance, just as the hands of a broken clock point to the right time twice a day. This work highlights how proxy climate data sets can sometimes provide more insights than instrumental climate data alone.