With March drawing to a close, Winter should now be safely behind us. For people in much of the US it has doubtless been a long one. Here in Florida it obviously is always warmer than where the rest of you are, but for me it was long enough-interestingly, the summer of 2009 was very hot here, so sort of a swing between extremes we’ve had. I decided to make some comments on the winter that has just passed because from a climate/weather standpoint it was very interesting. Not so much for what it says about warming (not much at all if anything) but for the particular pattern we’ve just seen.
There can be little doubt that this last winter was a crazy one-plenty of warmth hid at the poles where nobody would have noticed if they went by their experiences alone. When talking about large scale patterns, one can almost make out the path of the Jet Stream in the NH where a surprising dent was made in the Siberian Hotspot, bent southward over the Pacific and gave a classic “El Nino” pattern (that’s possibly debatable) in the US, and drifted North up to Europe looping back to Siberia. Outside of that cold belt it was relatively warm in most places, with a classic negative Arctic Oscillation “blocking” Highs pattern. The reason this winter is interesting, to me, is that it illustrates the role of ocean and atmospheric dynamics in causing variations in seasonal weather. My (heretical) conjecture is that the right pattern of such dynamics can result in “global warming” and also “global cooling”, and that the potential that such dynamics have to cause long term changes in climate has not been considered thoroughly enough by those claiming they can “attribute” the observed changes.