This is one of the reasons severe weather has been on the decrease. Less variance means less mixing, and mixing of extreme temperature differential air masses is what contributes to volatile weather events like tornado outbreaks.
Source: http://www1.ncdc.noaa.gov/pub/data/cmb/images/tornado/clim/EF3-EF5.png
Here is the paper:
Arctic amplification decreases temperature variance in northern mid- to high-latitudes
James A. Screen Nature Climate Change (2014) doi:10.1038/nclimate2268
Changes in climate variability are arguably more important for society and ecosystems than changes in mean climate, especially if they translate into altered extremes1, 2, 3. There is a common perception and growing concern that human-induced climate change will lead to more volatile and extreme weather4. Certain types of extreme weather have increased in frequency and/or severity5, 6, 7, in part because of a shift in mean climate but also because of changing variability1, 2, 3, 8, 9, 10. In spite of mean climate warming, an ostensibly large number of high-impact cold extremes have occurred in the Northern Hemisphere mid-latitudes over the past decade11.
One explanation is that Arctic amplification—the greater warming of the Arctic compared with lower latitudes12 associated with diminishing sea ice and snow cover—is altering the polar jet stream and increasing temperature variability13, 14, 15, 16. This study shows, however, that subseasonal cold-season temperature variability has significantly decreased over the mid- to high-latitude Northern Hemisphere in recent decades. This is partly because northerly winds and associated cold days are warming more rapidly than southerly winds and warm days, and so Arctic amplification acts to reduce subseasonal temperature variance.
Previous hypotheses linking Arctic amplification to increased weather extremes invoke dynamical changes in atmospheric circulation11, 13, 14, 15, 16, which are hard to detect in present observations17, 18 and highly uncertain in the future19, 20. In contrast, decreases in subseasonal cold-season temperature variability, in accordance with the mechanism proposed here, are detectable in the observational record and are highly robust in twenty-first-century climate model simulations.
Source: http://ht.ly/2IgDV9
A non-paywalled presentation of the results is here: http://www.cesm.ucar.edu/working_groups/Polar/presentations/2014/screen.pdf
Zeke Hausfather notes:
Part of a growing consensus that a warmer world would, on balance, have less variance in temperature, particulary high-latitude areas. I wrote a bit about it here: http://www.yaleclimatemediaforum.org/2014/06/more-temperature-variability-in-a-warming-world-not-so/
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This is all just more of the same. Everything that happens weather-wise is consistent with the manmade climate change meme. The only thing that isn’t, and scares the bejesus out of them is the near-18 year halt in the warming. Weather is their last refuge, their Last Hurrah. More violent weather? Manmade climate. Less violent? Manmade climate. Same weather? Manmade climate.
They mean to say, we won’t know what weather is anymore.
The presentation is devoid of statistical significance rigor (IE no error bars and not a trace of statistical significance calculations) and serious attempts to factor in all other plausible causes of weather stability (natural AO oscillations, etc). Researchers these days simply refuse to investigate or consider the null hypothesis anymore. Rose colored glasses everywhere and an atmosphere of “I must be on the right track because I keep getting funded” is the new method of determining significance of any new idea, the null hypothesis be damned.
Idiots.
Zeke, Indeed but the foreword of Anthony does.
Looking at the tornado graph, it’s almost as if there was a great climate shift of 1976.
Less temperature variability in NH climate is a prelude to another 90,000 year glaciation episode. Earth will merely sink to its normal default status during this current Ice Age, which has been going on for the last 3 million years.
Yep. And when the climate swings back the other way, Al Gore’s hair will catch fire and his arms will begin waiving and he will say “SEE! I TOLD YOU CO2 would cause extreme weather!”
Here is the other side of the coin, so to speak.
Great storms of the Little Ice Age.