The European Beech Annual Tree Ring Widths Time Series, Solar–Climatic Relationships and Solar Dynamo Regime Changes

Abstract

In this study, the results from the analysis of annual ring widths (‘Dm’) time series of two “very sensitive” to the climate and solar–climate relationships of long lived European beech (Fagus sylvatica) samples (on age of 209 ± 1 and 245 ± 5 years correspondingly) are discussed. Both series are characterized by very good expressed and relating to the solar magnetic Hale cycle 20–22-year oscillations. A good coincidence between the changes of ‘Dm’ and the growth or fading of the solar magnetic cycle is found. The transition effects at the beginning and ending of the grand Dalton (1793–1833) and Gleissberg minima (1898–1933) are very clearly visible in the annual tree ring width data for the one of beech samples. Some of these effects are also detected in the second sample. The problem for the possible “lost” sunspot cycle at the end of 18th century is also discussed. A prediction for a possible “phase catastrophe” during the future Zurich sunspot cycles 26 and 27 between 2035–2040 AD as well as for general precipitation upward and temperature fall tendencies in Central Bulgaria, more essential after 2030 AD, are brought forth.

About the Possible Solar Nature of the ~200 yr (de Vries/Suess) and ~2000–2500 yr (Hallstadt) Cycles and Their Influences on the Earth’s Climate: The Role of Solar-Triggered Tectonic Processes in General “Sun–Climate” Relationship

“…In the basic version, the TRPA was suggested by the author in 1986 [58]. Recently, additional improvements have been made by the author [28,46], as well as by Bonev et al [30]. The "standard mode" of TRPA was also recently described in detail in [46] (see also the brief description in Section 2.2.1).…”

“…The data for the 19th century used in this study are published in [55][56][57]. On the other hand, the data for the epoch 1780-1898 were complemented by the dendrochronological climatic data for the European beech (Fagus sylvatica) vegetation season (April-October) for the epoch 1780-1899 [46].…”

“…1. Time series analysis by using the T-R periodogram algorithm [28,45,46] of the last version of tree ring width 14 C series (INTCAL13) during the last 13,900 years (i.e., the most recent part of the Wurm ice epoch plus the Holocene) [47]. This task involves searching for the existence and statistical significance of cycles in the range of periods from 10 to 10,000 years with a focus on the Suess (200-210 yr) and Hallstadt (2000-2500 yr) cycles.…”

"Danjon Effect", Solar-Triggered Volcanic Activity, and Relation to Climate Change

“…In our opinion, the 3-year smoothing is optimal for the best discovery of length oscillations of about 11 years, i.e., the mean duration of Schwabe-Wolf's sunspot cycle. The smoothed residual time series has been studied for the existence of statistically significant cycles using two methods: the T-R periodogram algorithm [Komitov, 1997[Komitov, , 2021[Komitov, , 1986] and wavelet analysis [Torrence and Compo, 1998].…”

Effects of Climate Change on Scots Pine (Pinus sylvestris L.) Growth across Europe: Decrease of Tree-Ring Fluctuation and Amplification of Climate Stress

“…This cycle can be linked with the influence of the solar cycle that has been described for precipitation and temperature across Europe [122,123] and can be observed in the tree-ring series of many tree species. The 11-year growth cycle has been recorded on forest tree rings throughout Europe, on European beech, for example, in the Czech Republic, Italy [124][125][126], and Bulgaria [127]. Scots pine forests also reflected solar cycles, for example, in western Russia [87,88,120].…”