The following text has been sent in by Geert
Jan van Oldenborgh, Jos de Laat, Juerg Luterbacher, William Ingram and
Tim Osborn:
Claim of solar influence is on thin ice: are 11-year
cycle solar minima associated with severe winters in Europe?
Eight months year ago, news articles claimed that
scientists had discovered a strong connection between severe winters in central
Europe and the 11-year sunspot cycle. They were based on an article by Sirocko et al, ‘Solar
influence on winter severity in central Europe’ (Geophys. Res. Lett. 39 (2012) L16704),
which we shall call SBP. Fifty years ago, Lorenz showed
that a large part of the variability of winter weather is due to deterministic
chaos, i.e., unpredictable fluctuations in atmospheric circulation,
particularly in the westerly flow. The role of external forcings (including
solar activity) in determining the warmth of individual winters is expected,
therefore, to be rather minor – or even negligible if the forcing changes are
weak. This has indeed been found in many review articles. SBP was therefore at
odds with the current scientific consensus that the role of the
sunspot cycle in the climate is small. We investigated why SBP
had such unexpected results and came up with a number of
fundamental issues with this paper Our results have just been published in Environmental Research Letters, http://iopscience.iop.org/1748-9326/8/2/024014
(open access)
Posts
