Saratov Branch of V.A. Kotel'nikov Institute of Radio Engineering and Electronics of the Russian Academy of Sciences, 38 Zelyonaya St., Saratov, 410019, Russia.
Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanova St., Nizhny Novgorod, 603950, Russia.
Sci Rep. 2017 Sep 11;7(1):11131. doi: 10.1038/s41598-017-11340-8.
Understanding the influence of changes in solar activity on Earth's climate and distinguishing it from other forcings, such as volcanic activity, remains a major challenge for palaeoclimatology. This problem is best approached by investigating how these variables influenced past climate conditions as recorded in high precision paleoclimate archives. In particular, determining if the climate system response to these forcings changes through time is critical. Here we use the Wiener-Granger causality approach along with well-established cross-correlation analysis to investigate the causal relationship between solar activity, volcanic forcing, and climate as reflected in well-established Intertropical Convergence Zone (ITCZ) rainfall proxy records from Yok Balum Cave, southern Belize. Our analysis reveals a consistent influence of volcanic activity on regional Central American climate over the last two millennia. However, the coupling between solar variability and local climate varied with time, with a regime shift around 1000-1300 CE after which the solar-climate coupling weakened considerably.
理解太阳活动变化对地球气候的影响，并将其与其他强迫因素（如火山活动）区分开来，仍然是古气候学的一个主要挑战。通过研究这些变量如何影响过去气候条件，在高精度古气候档案中记录下来，是解决这个问题的最佳方法。特别是，确定气候系统对这些强迫因素的响应是否随时间变化是至关重要的。在这里，我们使用 Wiener-Granger 因果关系方法以及成熟的交叉相关分析，来研究太阳活动、火山强迫与气候之间的因果关系，这些关系反映在伯利兹南部 Yok Balum 洞穴中成熟的热带辐合带（ITCZ）降水代用记录中。我们的分析揭示了过去两千年中，火山活动对中美洲地区气候的持续影响。然而，太阳变化和当地气候之间的耦合随时间而变化，在公元 1000-1300 年左右发生了一次体制转变，此后太阳-气候的耦合大大减弱。
