Drew Shindell, NASA modeller who works with James Hansen showed here
in a paper in Science (2001) how low solar periods with reduced ultraviolet leads to less ozone chemistry warming in high altitudes over low and mid latitudes. This apparently allows for cooling and expansion of the polar vortex and more blocking in high latitudes (a negative NAO/AO).
Here Shindell shows the difference between the Maunder Minimum temperatures of 1680 and those of much more active sun period 1780. You clearly see the negative NAO and AO and a cold winter in the continents in the low sun period.
Writing in Environmental Research Letters (2010), Mike Lockwood et al. have verified that solar activity does seem to have a direct correlation with Earth's climate by influencing North Atlantic blocking (NAO) as Shindell has shown.
to download PDF file to read FULL report from Joseph D’Aleo, CCM at IceCap.us