Bezymianny the next high latitude impact volcano? «

Climatologists may disagree on how much the recent global warming is natural or manmade but there is general agreement that volcanism constitutes a wildcard in climate, producing significant global scale cooling for at least a few years following significant eruptions. However, there are some interesting seasonal and regional variations of the effects.

Oman and Robock (2003) and others have shown that though major volcanic eruptions seem to have their greatest cooling effect in the summer months, the location of the volcano determines whether the winters are colder or warmer over large parts of North America and Eurasia. According to Oman, tropical region volcanoes like El Chichon and Pinatubo actually produce a warming in winter due to a tendency for a more positive North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) – below left top and bottom. In the positive phase of these large scale pressure oscillations, low pressure and cold air is trapped in high latitudes and the resulting more westerly jet stream winds drives milder maritime air into the continents.

Volcano Eruptions & Climate Change | Extreme Cold Winters, Weather & Climate Extremes | Laki Volcano, Iceland | Our Amazing Planet

The eruption of a volcano in Iceland is often blamed for the unusually harsh winter of 1783 to 1784 around the North Atlantic. But new research lays the blame for the extreme cold elsewhere.

Scientists find that the extremes of cold back then might actually have been triggered by the same climate effects potentially responsible for the unusually cold and snowy winter that Europe and North America experienced from 2009 to 2010.

These new findings shed light on how extremes in natural variability in climate have played — and still play — a key role in our world today, along with any recent global warming effects, the researchers said.