Solar Activity Linked To Periodic Climate Change During The Holocene

Several intervals of significant rapid climate change were detected during the Holocene at 10.3, 9.3-9.5, around 8.2, 6.4-6.2, 4.7-4.5, and around 2.7 ka BP. Those intervals are similar to the cold events evidenced in different natural paleoclimate archivers, suggesting common climate forcing mechanisms related to changes in solar irradiance.

Abstract. We present a decadal-centennial scale Holocene climate record based on trace elements contents from a 65 cm stalagmite (“Père Noël”) from Belgian Père Noël cave. Père Noël (PN) stalagmite covers the last 12.7 ka according to U/Th dating. High spatial resolution measurements of trace elements (Sr, Ba, Mg and Al) were done by LaserAblation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). Trace elements profiles were interpreted as environmental and climate changes in the Han-sur-Lesse region. Power spectrum estimators and continuous wavelet 15 transform were applied on trace elements time series to detect any statistically significant periodicities in the PN stalagmite. Spectral analyses reveal decadal to millennial periodicities (i.e., 68-75, 133-136, 198-209, 291-358, 404- 602, 912-1029 and 2365-2670 yr) in the speleothem record. Results were compared to reconstructed sunspot number data to determine whether solar signal is presents in PN speleothem. The occurrence of significant solar periodicities (i.e., cycles of Gleissberg, de Vries, unnamed 500 years, Eddy and Hallstat) supports for an impact of solar forcing on 20 PN speleothem trace elements contents. Moreover, several intervals of significant rapid climate change were detected during the Holocene at 10.3, 9.3-9.5, around 8.2, 6.4-6.2, 4.7-4.5, and around 2.7 ka BP. Those intervals are similar to the cold events evidenced in different natural paleoclimate archivers, suggesting common climate forcing mechanisms related to changes in solar irradiance. […]

6. Conclusion We have shown that the high-resolution trace element records obtained by LA-ICP-MS from the PN stalagmite provide a detailed paleoclimate and/or paleoenvironment record of Northwestern Europe through the Holocene. The strong covariation of trace elements (Ba, Sr, Mg and Al), and with δ18O, confirms a common or strongly related controlling process. Based on trace element time-series we demonstrate that several events at 10.3, 9.3-9.5, around 8.2, 6.4-6.2, 4.7-4.5, and around 2.7 ka BP alternate with periods of relatively stable and wet/warmer climate. These intervals coincide with the cold events defined in marine and continental archives. The trace element time-series of the PN speleothem reveals a significant correlation with sunspot number records, suggesting some solar forcing in the PN trace elemental records. This observation is confirmed by wavelet analyses that reveal common solar periodicities (Gleissberg cycle, de Vries cycle, unnamed 500 year, Eddy cycles, and Hallstatt cycle) in agreement with those recognized in the North Atlantic marine cores and the Greenland ice cores, as well as some other terrestrial Holocene records, suggesting common forcing mechanisms. Our study, based on high-resolution LA-ICP-MS analyses, emphasizes that speleothem trace element profiles may be considered as a new solar activity proxy on decadalcentennial timescales over the Holocene.