|2011-09-03 03:24:02||Recent warm and cold daily winter temperature extremes in the Northern Hemisphere|
Just stumbled across this paper. Yet i'm sure the deniers are styill talking about how the cold weather in Eurasia th epast two winter sis indicative of a looming ice age. Frtom the sbatract:
"The winters of 2009–2010 and 2010–2011 brought frigid temperatures to parts of Europe, Russia, and the U.S. We analyzed regional and Northern Hemispheric (NH) daily temperature extremes for these two consecutive winters in the historical context of the past 63 years. While some parts clearly experienced very cold temperatures, the NH was not anomalously cold. Extreme warm events were much more prevalent in both magnitude and spatial extent. Importantly, the persistent negative state of the North Atlantic Oscillation (NAO) explained the bulk of the observed cold anomalies, however the warm extremes were anomalous even accounting for the NAO and also considering the states of the Pacific Decadal Oscillation (PDO) and El Niño Southern Oscillation (ENSO). These winters' widespread and intense warm extremes together with a continuing hemispheric decline in cold snap activity was a pattern fully consistent with a continuation of the warming trend observed in recent decades."
We had a recent cold snap in NZ that was truly anomalous - it snowed only 60km/h down the road from where I live! The last time this occurred was in 1939. A week later it was 18-19°C. In my neck of the woods the weather seems to be getting increasingly erratic. Late Autumn/early winter had record warmth.
In warmer periods of the Earth's history, the poles were much, much warmer than today and the equator-to-pole temperature gradient much smaller. If the past is a guide for future warming, then we may see the current pattern of warming start to break down. I wonder if weakening of the circumpolar winds is to be expected in the future? So we get more frequent polar blasts, as warming at the poles ramps up.
I haven't looked into it in any great detail, but it's one of a few things that bugs me, and that we should write about at some point. Maybe even a specific rebuttal, for the next time it (warm Arctic/cold continent pattern) happens. I'm not sure the casual reader is aware that the Earth is still warmer than average during these cold snaps.