Impact of powerful volcanic eruptions and solar activity on the climate above the Arctic Circle

Abstract

The tree growth response in polar region (Kola Peninsula and Finnish Lapland) to the most powerful (VEI>4) volcanic eruptions is assessed over a period of 1445-2005. The analysis was based on the Loparskaya (1445-2005) and Finnish supra-long (~ 7500 years) tree-ring chronologies. These chronologies were developed from Pinus sylvestris L. samples collected near the northern tree line at Loparskaya station (68.63o N, 33.25o E) and Finnish Lapland (68-70o N; 20-30o E), respectively. A superposed epoch analysis indicated a significant decrease in polar tree-ring growth over 7 years after the eruptions with subsequent recovery to its normal level. The level of tree growth in polar region is affected by most powerful low-latitude volcanic eruptions. By contrast, high-latitude Icelandic volcanoes have no significant impact on the climate of Kola Peninsula and Finnish Lapland. The application of wavelet analysis for the Loparskaya tree ring chronology allowed to identify the existence of the main cycles of solar activity (11, 20-25, and ~ 100 years). Moreover, the wavelet analysis revealed a strong coherence in the 8-13 and 20-30 year bands, indicating a possible link between solar activity and climate change on a regional scale.