Was gibt es Neues von der Sonne? Eine Übersicht zu aktuellen Arbeiten im Themenkomplex Sonne-Klima

Vor mehr als drei Jahren erschien (im Februar 2012) unser Buch Die kalte Sonne. Darin beschrieben wir eine Vielzahl von wissenschaftlichen Ergebnissen, die eine signifikante Beteiligung von Sonnenaktivitätsschwankungen am Klimageschehen nahelegen. Führende deutsche Klimawissenschaftler fühlten, dass Ihr CO2-dominiertes Weltbild plötzlich in Gefahr geriet und kämpften aktiv gegen die Sonne an.

Mit etwas Abstand ist dem einen oder anderen IPCC-Klimakämpfer die überzogene Reaktion vielleicht sogar peinlich geworden. Mittlerweile wird immer klarer, dass man die klimatische Rolle der Sonne wohl lange Zeit unterschätzt hatte. Hierauf weisen auch aktuelle Studien hin, die wir in den kommenden Tagen hier im Blog zusammenfassen möchten. Was gibt es eigentlich Neues von der Sonne?

Erste Anlaufstelle zur Literaturrecherche ist die Webseite „Club de Soleil“ die vom Klimaforscher Maarten Blaauw von der Queen’s University of Belfast betrieben wird. Allein für 2015 hat Blaauw bis jetzt 23 Arbeiten vorgestellt, und ein Drittel des Jahres steht sogar noch aus. Hochaktuell sind auch zwei zusammenfassende Arbeiten von David Douglass und Robert Knox, die im April 2015 in Physics Letters A erschienen sind. Die Autoren fanden ein klares solares Signal in den Ozeantemperaturen:

Teil 1:
The Sun is the climate pacemaker I. Equatorial Pacific Ocean temperatures
Equatorial Pacific Ocean temperature time series data contain segments showing both a phase-locked annual signal and a phase-locked signal of period two years or three years, both locked to the annual solar cycle. Three such segments are observed between 1990 and 2014. It is asserted that these are caused by a solar forcing at a frequency of 1.0 cycle/yr. These periodic features are also found in global climate data (following paper). The analysis makes use of a twelve-month filter that cleanly separates seasonal effects from data. This is found to be significant for understanding the El Niño/La Niña phenomenon.

Teil 2:
The Sun is the climate pacemaker II. Global ocean temperatures
In part I, equatorial Pacific Ocean temperature index SST3.4 was found to have segments during 1990–2014 showing a phase-locked annual signal and phase-locked signals of 2- or 3-year periods. Phase locking is to an inferred solar forcing of 1.0 cycle/yr. Here the study extends to the global ocean, from surface to 700 and 2000 m. The same phase-locking phenomena are found. The El Niño/La Niña effect diffuses into the world oceans with a delay of about two months.

Siehe auch Besprechung der Arbeiten auf WUWT.

Im April 2014 wies das Blog The Hockey Schtick darauf hin, dass eine zeitliche Aufsummierung der Sonnenaktivität möglicherweise ein viel besserer Ansatz für den Vergleich mit der Temperaturentwicklung darstellt. Begründet werden kann dies durch die große Trägheit des Klimasystems. Plotten Sie es hier einmal selber. Das Ergebnis ist erstaunlich.

Interessant ist auch eine chinesische Arbeit aus dem Juni 2014 über das Science China Press die folgende Pressemitteilung herausgab:

Has solar activity influence on the Earth’s global warming?

A recent study demonstrates the existence of significant resonance cycles and high correlations between solar activity and the Earth’s averaged surface temperature during centuries. This provides a new clue to reveal the phenomenon of global warming in recent years.

Their work, entitled “Periodicities of solar activity and the surface temperature variation of the Earth and their correlations” was published in CHINESE SCIENCE BULLETIN (In Chinese) 2014 No.14 with the co-corresponding authors of Dr. Zhao Xinhua and Dr. Feng Xueshang from State key laboratory of space weather, CSSAR/NSSC, Chinese Academy of Sciences. It adopts the wavelet analysis technique and cross correlation method to investigate the periodicities of solar activity and the Earth’s temperature as well as their correlations during the past centuries.

Global warming is one of the hottest and most debatable issues at present. The Intergovernmental Panel on Climate Change (IPCC) claimed that the release of the anthropogenic greenhouse gases contributed to 90% or even higher of the observed increase in the global average temperature in the past 50 years. However, the debate on the causes of the global warming never stops. Research shows that the current warming does not exceed the natural fluctuations of climate. The climate models of IPCC seem to underestimate the impact of natural factors on the climate change, while overstate that of human activities. Solar activity is an important ingredient of natural driving forces of climate. Therefore, it is valuable to investigate the influence of solar variability on the Earth’s climate change on long time scales.

This innovative study combines the measured data with those reconstructed to disclose the periodicities of solar activity during centuries and their correlations with the Earth’s temperature. The obtained results demonstrate that solar activity and the Earth’s temperature have significant resonance cycles, and the Earth’s temperature has periodic variations similar to those of solar activity (Figure 1). This study also implies that the “modern maximum” of solar activity agrees well with the recent global warming of the Earth. A significant correlation between them can be found (Figure 2). As pointed out by a peer reviewer, “this work provides a possible explanation for the global warming”.

See the article:

ZHAO X H, FENG X S. Periodicities of solar activity and the surface temperature variation of the Earth and their correlations (in Chinese). Chin Sci Bull (Chin Ver), 2014, 59: 1284, doi: 10.1360/972013-1089 http://csb.scichina.com:8080/kxtb/CN/abstract/abstract514043.shtml

Science China Press Co., Ltd. (SCP) is a scientific journal publishing company of the Chinese Academy of Sciences (CAS). For 60 years, SCP takes its mission to present to the world the best achievements by Chinese scientists on various fields of natural sciences researches.

http://www.scichina.com/

Maliniemi und Kollegen beschrieben im August 2014 im Journal of Geophysical Research einen Zusammenhang der Wintertemperaturen auf der Nordhemisphäre mit dem Sonnenfleckenzyklus:

Spatial distribution of Northern Hemisphere winter temperatures during different phases of the solar cycle
Several recent studies have found variability in the Northern Hemisphere winter climate related to different parameters of solar activity. While these results consistently indicate some kind of solar modulation of tropospheric and stratospheric circulation and surface temperature, opinions on the exact mechanism and the solar driver differ. Proposed drivers include, e.g., total solar irradiance (TSI), solar UV radiation, galactic cosmic rays, and magnetospheric energetic particles. While some of these drivers are difficult to distinguish because of their closely similar variation over the solar cycle, other suggested drivers have clear differences in their solar cycle evolution. For example, geomagnetic activity and magnetospheric particle fluxes peak in the declining phase of the sunspot cycle, in difference to TSI and UV radiation which more closely follow sunspots. Using 13 solar cycles (1869–2009), we study winter surface temperatures and North Atlantic oscillation (NAO) during four different phases of the sunspot cycle: minimum, ascending, maximum, and declining phase. We find significant differences in the temperature patterns between the four cycle phases, which indicates a solar cycle modulation of winter surface temperatures. However, the clearest pattern of the temperature anomalies is not found during sunspot maximum or minimum, but during the declining phase, when the temperature pattern closely resembles the pattern found during positive NAO. Moreover, we find the same pattern during the low sunspot activity cycles of 100 years ago, suggesting that the pattern is largely independent of the overall level of solar activity.

 

Und schließlich wollen wir noch ein Paper von Nicola Scafetta vorstellen, das im November 2014 in der Elsevier-Zeitschrift Physica A: Statistical Mechanics and its Applications erschienen ist. Es handelt sich um eine Diskussion einer Arbeit von Gil-Alana et al., in der die Autoren behauptet hatten, Sonnenaktivitätsschwankungen hätten keinen Einfluss auf das Klima. Scafetta zeigt, dass es durchaus einen Zusammenhang gibt, der jedoch komplexer ist als von Gil-Alana und Kollegen angenommen. Hier der Abstract von Scafetta‘s Diskussion:

Global temperatures and sunspot numbers. Are they related? Yes, but non linearly. A reply to Gil-Alana et al. (2014)
Recently Gil-Alana et al. (2014) compared the sunspot number record and the temperature record and found that they differ: the sunspot number record is characterized by a dominant 11-year cycle while the temperature record appears to be characterized by a “singularity” or “pole” in the spectral density function at the “zero  ” frequency. Consequently, they claimed that the two records are characterized by substantially different statistical fractional models and rejected the hypothesis that the Sun influences significantly global temperatures. I will show that: (1) the “singularity” or “pole” in the spectral density function of the global surface temperature at the “zero” frequency does not exist—the observed pattern derives from the post 1880 warming trend of the temperature signal and is a typical misinterpretation that discrete power spectra of non-stationary signals can suggest; (2) appropriate continuous periodograms clarify the issue and also show a signature of the 11-year solar cycle (amplitude ≤0.1°C), which since 1850 has an average period of about 10.4 year, and of many other natural oscillations; (3) the solar signature in the surface temperature record can be recognized only using specific techniques of analysis that take into account non-linearity and filtering of the multiple climate change contributions; (4) the post 1880-year temperature warming trend cannot be compared or studied against the sunspot record and its 11-year cycle, but requires solar proxy models showing short and long scale oscillations plus the contribution of anthropogenic forcings, as done in the literature. Multiple evidences suggest that global temperatures and sunspot numbers are quite related to each other at multiple time scales. Thus, they are characterized by cyclical fractional models. However, solar and climatic indexes are related to each other through complex and non-linear processes. Finally, I show that the prediction of a semi-empirical model for the global surface temperature based on astronomical oscillations and anthropogenic forcing proposed by Scafetta since 2009 has, up to date, been successful.