Weather And The Iceland Volcano

[submarinesailor]

I received this in one of my on-line energy trade rags talking about how this eruption COULD possibly have an effect on our weather.

http://www.timesonline.co.uk/tol/news/weather/article7074418.ece

Some questions have come up today regarding what climate impacts the volcanic eruption in Iceland will have.  The most recent eruption has produced an ash plume up to 11 km (~35,000 feet) which is high enough to have some long lasting impacts depending on the amount of sulfur dioxide gas that was emitted.  Ash emissions themselves have little impact on climate, except locally, since most of the ash falls out within a matter of days.  Any SO2 that reaches the stratosphere can remain in place for a few years, however.  It is uncertain at this time whether the eruption has been large enough to have much long lasting climate impact, but certainly any additional eruptions (which will probably occur) would increase the chances for more significant impacts.  Eruptions at Mt. Redoubt in Alaska as well as on the Kamchatka peninsula in Russia about this time last year did have some cooling influence on summer temperatures last year as well as this past winter.    So, should the eruptions continue (generally only those that produce plumes in excess of 8km will have a lasting impact), temperatures this summer could end up somewhat cooler than currently expected and there would also be potential for some a cooling influence next winter.

As a rule of thumb, significant volcanic eruptions in the tropics will have an impact globally in which summers tend to be cooler, but winters warmer across the U.S. and Europe.   Significant high-latitude volcanic eruptions tend to only impact the hemisphere in which they occur.  High latitude northern hemisphere eruptions tend to have a cooling influence on both winter and summer temperatures across the U.S. and Europe.

Bruce

[Gary_C]

That's very interesting. I thought I once read that after some volcanic eruptions some parts of the globe had a summer without sun when the ash in the upper atmosphere forms a band around the globe and blocks the sun. It can also have an impact on growing conditions as there is less sunlight hitting the earth.

[JohnG28]

That is very interesting indeed. In fact, that could actually show some of the reason last summer was so much cooler than usual here.  It was one miserable, cold, rainy excuse for a summer.  We can hope that this is not the case this year, and certainly hope not to see more eruptions, both for the global impact as well as those in the area directly affected.