...This study shows that the hypothesis that LIA cooling is related to a circulation in the North Atlantic sector with a persistently negative NAO-index is unlikely to be valid. The model results do not convincingly reproduce the overall winter cooling see in Europe during the LIA period and persistence of this cooling into the summer season is weak.
The hosing experiments do not clearly support the hypothesis that a reduction in the MOC is the primary driver of LIA climate change. The hosing experiment with the ECBilt-Clio model shows a cooling which has similarities with the reconstructed temperatures for the LIA climate, but the largest cooling is off-shore. The reconstructions have their greatest cooling in eastern Europe which hints at a change in atmospheric circulation as an explanation for this pattern. Moreover, these experiments shows no similarity with the character of the reconstructed summer temperature signal either, which may have persisted from the preceeding winter, due to the conservative nature of surface ocean temperatures or soil moisture.