Die Sonnenaktivität schwankt im Rhythmus recht gut bekannter Zyklen, darunter der Gleissbergzyklus im Bereich von 90 Jahren plusminus 30 Jahre. Im März 2015 erschien im Fachblatt Advances in Space Research eine Arbeit von Orgutsov et al. die eine solare Gleissberg-Zyklik in der Dauer der Wachstumsperiode der nördlichen Hemisphäre während der vergangenen 450 Jahre entdeckte. Die Autoren vermuten eine solare Beeinflussung der Temperaturen mit Auswirkungen auf das Pflanzenwachstum. Hier der Abstract:
Evidence for the Gleissberg solar cycle at the high-latitudes of the Northern Hemisphere
Time evolution of growing season temperatures in the Northern Hemisphere was analyzed using both wavelet and Fourier approaches. A century-scale (60–140 year) cyclicity was found in the summer temperature reconstruction from the Taymir peninsula (∼72° N, ∼105° E) and other high-latitude (60–70° N) regions during the time interval AD 1576–1970. This periodicity is significant and consists of two oscillation modes, 60–70 year and 120–140 year variations. In the summer temperatures from the Yamal peninsula (∼70° N, ∼67° E) only a shorter-term (60–70 year) variation is present. A comparison of the secular variation in the Northern Hemisphere temperature proxies with the corresponding variations in sunspot numbers and the fluxes of cosmogenic 10Be in Greenland ice shows that a probable cause of this variability is the modulation of temperature by the century-scale solar cycle of Gleissberg. This is consistent with the results obtained previously for Northern Fennoscandia (67°–70° N, 19°–33° E). Thus, evidence for a connection between century-long variations in solar activity and climate was obtained for the entire boreal zone of the Northern Hemisphere.
Ein Jahr zuvor hatte Ogurtsov zusammen mit einem finnischen Kollegen im Journal of Atmospheric and Solar-Terrestrial Physics bereits eine weitere Arbeit zum Gleissberg-Zyklus veröffentlicht. Damals berichteten Sie über eine solare Gleissbergzyklik in Nitratkonzentrationen in polaren Eisarchiven:
Evidence of the solar Gleissberg cycle in the nitrate concentration in polar ice
Two sets of nitrate (NO3−) concentration data, obtained from Central Greenland and East Antarctic (Dronning Maud Land) ice cores, were analyzed statistically. Distinct century-scale (50–150 yr) variability was revealed in both data sets during AD 1576–1990. It was found that century-type variation in Greenland and Antarctic nitrate correlates fairly significantly with the corresponding Gleissberg cycle: (a) in sunspot number over 1700–1970 AD; (b) in 10Be concentration in Central and South Greenland over 1576–1970 AD. Thus, presence of century-scale relationship between polar nitrate and solar activity was confirmed over the last 4 centuries. That proves that NO3− concentration in polar ice caps could serve as indicator of long-term solar variability.
Ein weiterer wichtiger solarer Zyklus ist der Suess-de Vries-Zyklus. Hans-Joachim Lüdecke hat mit den Kollegen Weiss und Hempelmann im Februar 2015 im Fachblatt Climate of the Past Discussions eine Übersicht zur klimatischen Verknüpfung dieses solaren Zyklus veröffentlicht:
Paleoclimate forcing by the solar De Vries/Suess cycle
A large number of investigations of paleoclimate have noted the influence of a ~ 200 year oscillation which has been related to the De Vries/Suess cycle of solar activity. As such studies were concerned mostly with local climate, we have used extensive northern hemispheric proxy data sets of Büntgen and of Christiansen/Ljungqvist together with a southern hemispheric tree-ring set, all with 1 year time resolution, to analyze the climate influence of the solar cycle. As there is increasing interest in temperature rise rates, as opposed to present absolute temperatures, we have analyzed temperature differences over 100 years to shed light on climate dynamics of at least the last 2500 years. Fourier- and Wavelet transforms as well as nonlinear optimization to sine functions show the dominance of the ∼ 200 year cycle. The sine wave character of the climate oscillations permits an approximate prediction of the near future climate.
In Übereinstimmung mit diesem Paper steht eine Studie von Tiwari und Rajesh, die im Mai 2014 in den Geophysical Research Letters erschien. Die Autoren fanden die Suess-de Vries-Zyklik in der Niederschlagsverteilung in Nordwest China während der vergangenen 700 Jahre:
Imprint of long-term solar signal in groundwater recharge fluctuation rates from Northwest China
Multiple spectral and statistical analyses of a 700 yearlong temporal record of groundwater recharge from the dry lands, Badain Jaran Desert (Inner Mongolia) of Northwest China reveal a stationary harmonic cycle at ~200 ± 20 years. Interestingly, the underlying periodicity in groundwater recharge fluctuations is similar to those of solar-induced climate cycle “Suess wiggles” and appears to be coherent with phases of the climate fluctuations and solar cycles. Matching periodicity of groundwater recharge rates and solar and climate cycles renders a strong impression that solar-induced climate signals may act as a critical amplifier for driving the underlying hydrographic cycle through the common coupling of long-term Sun-climate groundwater linkages.
