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German scientists Lüning and Vahrenholt bring up two recent papers on what by now is obvious to almost everyone.

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By Dr. Sebastian Lüning and Prof. Fritz Vahrenholt

(German text translated/edited by P Gosselin)

Antarctica is a fantastic place for a research laboratory. A number of research stations are scattered on the continent, including the Russian Vostok station.

Using ice cores, the climate history of the past 11,000 years has been reconstructed in detail. In January 2015 Zhao and Feng published a paper in the Journal of Atmospheric and Solar-Terrestrial Physics. In this paper they compared the temperature development to solar activity. In the temperature curve the scientists found the characteristic cycles that correspond to the solar Suess-de Vries cycle (208 years) and the Eddy cycle (1000 years). What stood out was the slight time delay of 30 to 40 years between the solar trigger and the temperature reaction. The scientists concluded that solar activity fluctuations played a large role in the development of the Antarctic climate.

Here’s the abstract:

Correlation between solar activity and the local temperature of Antarctica during the past 11,000 years

The solar impact on the Earth’s climate change is a long topic with intense debates. Based on the reconstructed data of solar sunspot number (SSN), the local temperature in Vostok (T), and the atmospheric CO 2 concentration data of Dome Concordia, we investigate the periodicities of solar activity, the atmospheric CO 2 and local temperature in the inland Antarctica as well as their correlations during the past 11,000 years before AD 1895. We find that the variations of SSN and T have some common periodicities, such as the 208 year (yr), 521 yr, and ~1000 yr cycles. The correlations between SSN and T are strong for some intermittent periodicities. However, the wavelet analysis demonstrates that the relative phase relations between them usually do not hold stable except for the millennium-cycle component. The millennial variation of SSN leads that of T by 30–40 years, and the anti-phase relation between them keeps stable nearly over the whole 11,000 years of the past. As a contrast, the correlations between CO 2 and T are neither strong nor stable. These results indicate that solar activity might have potential influences on the long-term change of Vostok’s local climate during the past 11,000 years before modern industry.

Related to this is also a paper by Volobuev, which was published in the May 2014 journal of Climate Dynamics. For the region around the Vostok station the author described a “relatively high climate sensitivity” for the solar temperature drive. Here’s the abstract:

Central antarctic climate response to the solar cycle

Antarctic “Vostok” station works most closely to the center of the ice cap among permanent year-around stations. Climate conditions are exclusively stable: low precipitation level, cloudiness and wind velocity. These conditions can be considered as an ideal model laboratory to study the surface temperature response on solar irradiance variability during 11-year cycle of solar activity. Here we solve an inverse heat conductivity problem: calculate the boundary heat flux density (HFD) from known evolution of temperature. Using meteorological temperature record during (1958–2011) we calculated the HFD variation about 0.2–0.3 W/m2 in phase with solar activity cycle. This HFD variation is derived from 0.5 to 1 °C temperature variation and shows relatively high climate sensitivity per 0.1 % of solar radiation change. This effect can be due to the polar amplification phenomenon, which predicts a similar response 0.3–0.8 °C/0.1 % (Gal-Chen and Schneider in Tellus 28:108–121, 1975). The solar forcing (TSI) is disturbed by volcanic forcing (VF), so that their linear combination TSI + 0.5VF empirically provides higher correlation with HFD (r = 0.63 ± 0.22) than TSI (r = 0.50 ± 0.24) and VF (r = 0.41 ± 0.25) separately. TSI shows higher wavelet coherence and phase agreement with HFD than VF.”