Más sobre la conexión actividad solar/AO/tiempo invernal:
Solar forcing of winter climate variability in the Northern Hemisphere
http://conference2011.wcrp-climate.org/abstracts/C25/Smith_C25_W69B.pdfhttp://www.worldclimatereport.com/index.php/2011/10/24/natural-variability-still-plays-large-role-in-winter-climate/"A research team led by Sarah Ineson and primarily made up of scientists from the U.K.’s Hadley Centre Met Office have identified a fairly strong solar signal in Northern Hemisphere winter circulation patterns which are manifest over Europe and the eastern United States. According to their modeling studies, the difference in the amount of incoming solar radiation, in this case, primarily in the ultraviolet (UV) wavelengths, during the minima and maxima of the 11-yr solar cycle are large enough to produce a characteristic change in the winter circulation pattern of the atmosphere over North America. The patterns of circulation change induced by the sun are very similar to the positive and negative phases of the atmospheric circulation indices known as North Atlantic Oscillation (NAO) and the closely related Arctic Oscillation (AO). The NAO and AO are typically linked to winter weather on both sides of the Atlantic and sometimes with global warming.
The average of recent winters (2008/9, 2009/10 and 2010/11) shows cold conditions over northern Europe and the United States and mild conditions over Canada and the Mediterranean associated with anomalously low and even record low values of the NAO. …Given our modelling result, these cold winters were probably exacerbated by the recent prolonged and anomalously low solar minimum. On decadal timescales the increase in the NAO from the 1960s to 1990s…may also be partly explained by the upwards trend in solar activity evident in the open solar-flux record….
The solar effect presented here contributes a substantial fraction of typical year-to-year variations in near-surface circulation, with shifts of up to 50% of the interannual variability. This represents a substantial shift in the probability distribution for regional winter climate and a potentially useful source of predictability. Solar variability is therefore an important factor in determining the likelihood of similar winters in future. However, mid-latitude climate variability depends on many factors, not least internal variability, and forecast models that simulate all the relevant drivers are needed to estimate the range of possible winter conditions."
