Monat: Mai 2016

Die Sonne? Die habe doch gar keinen Einfluss auf das Klima. Daran wird zumindest in Klimaalarmistenkreisen stark geglaubt. Eine neue Studie vom 28. April 2016 aus den Geophysical Research Letters bringt das Weltbild nun endgültig ins Wanken. Forscher konnten zeigen, dass Änderungen der solaren UV-Strahlung im Monatsmaßstab einen deutlichen Einfluss auf die Temperaturen in den unteren Wetterstockwerken in den Tropen haben. Hier der Abstract der Arbeit von L. L. Hood von der Univeristy of Arizona in Tucson:

Lagged response of tropical tropospheric temperature to solar ultraviolet variations on intraseasonal time scales
Correlative and regression analyses of daily ERA-Interim reanalysis data for three separate solar maximum periods confirm the existence of a temperature response to short-term (mainly ∼27 day) solar ultraviolet variations at tropical latitudes in both the lower stratosphere and troposphere. The response, which occurs at a phase lag of 6–10 days after the solar forcing peak, consists of a warming in the lower stratosphere, consistent with relative downwelling and a slowing of the mean meridional (Brewer-Dobson) circulation, and a cooling in the troposphere. The midtropospheric cooling response is most significant in the tropical Pacific, especially under positive El Niño–Southern Oscillation conditions and may be related to a reduction in the number of Madden-Julian oscillation events that propagate eastward into the central Pacific following peaks in short-term solar forcing.

Thomas et al. fanden solar-gesteuerte Temperaturveränderungen in der Mesosphäre, die sie im November 2015 im Journal of Atmospheric and Solar-Terrestrial Physics beschrieben:

Solar-induced 27-day variations of mesospheric temperature and water vapor from the AIM SOFIE experiment: Drivers of polar mesospheric cloud variability
Polar Mesospheric Clouds (PMCs) are known to be influenced by changes in water vapor and temperature in the cold summertime mesopause. Solar variability of these constituents has been held responsible for 11-year and 27-day variability of PMC activity, although the detailed mechanisms are not yet understood. It is also known that the solar influence on PMC variability is a minor contributor to the overall day-to-day variability, which is dominated by effects of gravity waves, planetary waves, and inter-hemispheric coupling. To address this issue, we have analyzed 15 seasons of data taken from the Solar Occultation for Ice Experiment (SOFIE) on the Aeronomy of Ice in the Mesosphere (AIM) satellite. The SOFIE data contain precise measurements of water vapor, temperature and ice water content (among other quantities). These high-latitude measurements are made during the PMC season at the terminator, and therefore directly relate to the simultaneous measurements of mesospheric ice. Using a composite data set of Lyman-α irradiance, we correlated the time variation of the atmospheric variables with the 27-day variability of solar ultraviolet irradiance. We used a combination of time-lagged linear regression and Superposed Epoch Analysis to extract the solar contribution as sensitivity values (response/forcing) vs. height. We compare these results to previously published results, and show that the temperature sensitivity is somewhat higher, whereas the water sensitivity is nearly the same as published values. The time lags are shorter than that expected from direct solar heating and photodissociation, suggesting that the responses are due to 27-day variations of vertical winds. An analytic solution for temperature changes forced by solar irradiance variations suggests that if the response is due purely to Lyman-α heating and Newtonian cooling, the response should vary throughout the summertime season and depend primarily upon the height-dependent column density of molecular oxygen.

Einen spürbaren Klimaeinfluss von solaren UV-Schwankungen berichteten auch Ball et al. in einer Studie, die am 25. Januar 2016 in Nature Geoscience erschien. Interessantes Resultat: Die Modelle können die Realität nicht reproduzieren. Hier der Abstract:

High solar cycle spectral variations inconsistent with stratospheric ozone observations
Solar variability can influence surface climate, for example by affecting the mid-to-high-latitude surface pressure gradient associated with the North Atlantic Oscillation¹. One key mechanism behind such an influence is the absorption of solar ultraviolet (UV) radiation by ozone in the tropical stratosphere, a process that modifies temperature and wind patterns and hence wave propagation and atmospheric circulation^{2, 3, 4, 5}. The amplitude of UV variability is uncertain, yet it directly affects the magnitude of the climate response⁶: observations from the SOlar Radiation and Climate Experiment (SORCE) satellite⁷ show broadband changes up to three times larger than previous measurements^{8, 9}. Here we present estimates of the stratospheric ozone variability during the solar cycle. Specifically, we estimate the photolytic response of stratospheric ozone to changes in spectral solar irradiance by calculating the difference between a reference chemistry–climate model simulation of ozone variability driven only by transport (with no changes in solar irradiance) and observations of ozone concentrations. Subtracting the reference from simulations with time-varying irradiance, we can evaluate different data sets of measured and modelled spectral irradiance. We find that at altitudes above pressure levels of 5 hPa, the ozone response to solar variability simulated using the SORCE spectral solar irradiance data are inconsistent with the observations.

Die lange vernachlässigte Verknüpfung zwischen der Schwankungen der Sonnenaktivität und klimatischen Veränderungen an der Meeresoberfläche, Troposphäre und Stratosphäre beschrieben auch Yamakawa et al. im März 2016 im Fachblatt Quaternary International:

Relationships between solar activity and variations in SST and atmospheric circulation in the stratosphere and troposphere
Relationships between solar activity and variations in both sea surface temperature (SST) and atmospheric circulation at the time of the solar maximum are presented. The global distribution of correlation coefficients between annual relative sunspot numbers (SSN) and SST from July to December was examined over a 111-year period from 1901 to 2011. Areas with a significant positive correlation accounted for 11.7% of the global sea surface in December, mainly over three regions in the Pacific. The influence of solar activity on global atmospheric pressure variations and circulation in the maximum years was also analyzed from 1979 to 2011. The results indicated that higher geopotential height anomalies tended to appear in the stratosphere and troposphere in the northern hemisphere, centering on around the Hawaiian Islands from November to December, in the second year of the solar maximum. The SST distribution in the Pacific with strong north and south Pacific Highs produced a pattern that resembled teleconnection patterns such as the Pacific Decadal Oscillation (PDO) and the Central-Pacific (CP) El Niño, or El Niño Modoki (ENM). It is suggested that the solar activity had an influence on the troposphere via not only the stratosphere but also the sea surface.

In eine ähnliche Richtung geht eine Arbeit von Reichler et al., die bereits 2012 in Nature Geoscience erschienen war:

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Jeden Tag schiebt der Mond zwei Flutberge über den Planeten. An der nordamerikanischen Ostküste in der Bay of Fundy hebt und senkt sich das Meer dabei um satte 13 Meter. Da liegt es nahe, dass die Gezeitenkräfte von Mond, Planeten und Sonne auch bei der irdischen Klimagestaltung eine Rolle spielen. Nicola Scafetta, der bereits in unserem Buch „Die kalte Sonne“ als Gastautor dabei war, publizierte am 15. Mai 2016 in Advances in Space Research eine vergleichende Analyse zwischen den Planetenbewegungen und der Temperaturentwicklug auf der Erde während der vergangenen 165 Jahre. Dabei stieß Scafetta auf große Ähnlichkeiten und fand in den Datensätze immer wieder die Peridoden 20 und 60 Jahre. Die Erde und das Erdklima als Bestandteil des Planetensystems, ein nicht ganz abwegiger Gedanke. Hier die Kurzfassung der Arbeit:

High resolution coherence analysis between planetary and climate oscillations
This study investigates the existence of a multi-frequency spectral coherence between planetary and global surface temperature oscillations by using advanced techniques of coherence analysis and statistical significance tests. The performance of the standard Matlab mscohere algorithms is compared versus high resolution coherence analysis methodologies such as the canonical correlation analysis. The Matlab mscohere function highlights large coherence peaks at 20 and 60-year periods although, due to the shortness of the global surface temperature record (1850–2014), the statistical significance of the result depends on the specific window function adopted for pre-processing the data. In fact, window functions disrupt the low frequency component of the spectrum. On the contrary, using the canonical correlation analysis at least five coherent frequencies at the 95% significance level are found at the following periods: 6.6, 7.4, 14, 20 and 60 years. Thus, high resolution coherence analysis confirms that the climate system can be partially modulated by astronomical forces of gravitational, electromagnetic and solar origin. A possible chain of the physical causes explaining this coherence is briefly discussed.

Querdenker wie Scafetta haben es nicht leicht. Viele Kollegen hegen Skepsis gegenüber den vorgeschlagenen planetaren Mechanismen. Bereits 2014 ist Scafetta daher in die Offensive gegangen und versuchte in einem Beitrag in Astrophysics and Space Science die Argumente seiner Gegner zu klären. Hier die Kurzfassung:

Discussion on the spectral coherence between planetary, solar and climate oscillations: a reply to some critiques
During the last few years a number of works have proposed that planetary harmonics regulate solar oscillations. Also the Earth’s climate seems to present a signature of multiple astronomical harmonics. Herein I address some critiques claiming that planetary harmonics would not appear in the data. I will show that careful and improved analysis of the available data do support the planetary theory of solar and climate variation also in the critiqued cases. In particular, I show that: (1) high-resolution cosmogenic ¹⁰Be and ¹⁴C solar activity proxy records both during the Holocene and during the Marine Interglacial Stage 9.3 (MIS 9.3), 325–336 kyear ago, present four common spectral peaks (confidence level ⪆95 %) at about 103, 115, 130 and 150 years (this is the frequency band that generates Maunder and Dalton like grand solar minima) that can be deduced from a simple solar model based on a generic non-linear coupling between planetary and solar harmonics; (2) time-frequency analysis and advanced minimum variance distortion-less response (MVDR) magnitude squared coherence analysis confirm the existence of persistent astronomical harmonics in the climate records at the decadal and multidecadal scales when used with an appropriate window lenght (L≈110 years) to guarantee a sufficient spectral resolution to solve at least the major astronomical harmonics. The optimum theoretical window length deducible from astronomical considerations alone is, however, L⪆178.4 years because the planetary frequencies are harmonics of such a period. However, this length is larger than the available 164-year temperature signal. Thus, the best coherence test can be currently made only using a single window as long as the temperature instrumental record and comparing directly the temperature and astronomical spectra as done in Scafetta (J. Atmos. Sol. Terr. Phys. 72(13):951–970, 2010) and reconfirmed here. The existence of a spectral coherence between planetary, solar and climatic oscillations is confirmed at the following periods: 5.2 year, 5.93 year, 6.62 year, 7.42 year, 9.1 year (main lunar tidal cycle), 10.4 year (related to the 9.93–10.87–11.86 year solar cycle harmonics), 13.8-15.0 year, ∼20 year, ∼30 year and ∼61 year, 103 year, 115 year, 130 year, 150 year and about 1000 year. This work responds to the critiques of Cauquoin et al. (Astron. Astrophys. 561:A132, 2014), who ignored alternative planetary theories of solar variations, and of Holm (J. Atmos. Sol. Terr. Phys. 110–111:23–27, 2014a), who used inadequate physical and time frequency analyses of the data.

Nicola Scafetta steht mit seinem Modell zur planetaren Klimabeinflussung bei weitem nicht alleine da. Im Jahr 2014 erschien sogar ein Sonderband in der Fachzeitschrift Pattern Recognition in Physics mit dem Titel:

Pattern in solar variability, their planetary origin and terrestrial impacts

Darin enthalten ist unter anderem ein Beitrag von J.-E. Solheim:

The sunspot cycle length – modulated by planets?
The Schwabe frequency band of the sunspot record since 1700 has an average period of 11.06 yr and contains four major cycles, with periods of 9.97, 10.66, 11.01 and 11.83 yr. Analysis of the O–C residuals of the timing of solar cycle minima reveals that the solar cycle length is modulated by a secular period of about 190 yr and the Gleissberg period of about 86 yr. Based on a simple harmonic model with these periods, we predict that the solar cycle length will in average be longer during the 21st century. Cycle 24 may be about 12 yr long, while cycles 25 and 26 are estimated to be about 9 and 11 yr long. The following cycle is estimated to be 14 yr long. In all periods during the last 1000 yr, when the solar cycle length has increased due to the 190 yr cycle, a deep minimum of solar activity has occurred. This is expected to re-occur in the first part of this century. The coherent modulation of the solar cycle length over a period of 400 yr is a strong argument for an external tidal forcing by the planets Venus, Earth, Jupiter and Saturn, as expressed in a spin-orbit coupling model.

Interessant auch dieser Artikel aus dem selben Band von I. R. G. Wilson:

The Venus–Earth–Jupiter spin–orbit coupling model
A Venus–Earth–Jupiter spin–orbit coupling model is constructed from a combination of the Venus–Earth–Jupiter tidal-torquing model and the gear effect. The new model produces net tangential torques that act upon the outer convective layers of the Sun with periodicities that match many of the long-term cycles that are found in the ¹⁰Be and ¹⁴C proxy records of solar activity.

Siehe auch den folgenden Beitrag von 2012 aus dem Blog Astro-Climate-Connection:

Jupiter Tidal Torque Modell

Ebenfalls in Pattern Recognition in Physics erschien 2013 der folgende Artikel von J.-E. Solheim:

Signals from the planets, via the Sun to the Earth

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