Will the 2010 volcanic eruption in Iceland lead to a change in global weather patterns?
No. While the eruption certainly has had impact on aviation and the weather of the immediate area, the eruption will not have a global impact nor affect Wisconsin’s weather. In the April 14 – 19, 2010 eruptions of Eyjafjallajökull, the ash cloud debris remained in the troposphere at 12,000 feet and below. This caused havoc on aviation because jets must fly through this altitude and the ash poses danger to jet engines.
To have a global impact, the volcano must eject debris into the stratosphere. There it can last for a couple of years and be spread over the entire globe. By the ash reaching only into the troposphere, it can stay airborne for no more than a week due to precipitation processes, wind and gravity. The eruption also did not emit much sulfur dioxide, which can react chemically in the atmosphere to form tiny sulfuric acid droplets. These droplets, particularly if formed in the stratosphere, can reside for a few years and cause a cooling of the global surface temperatures because they reflect solar energy back to space. This was the case with Mt. Pinatubo in 1992.
Volcanic eruptions like Eyjafjallajökull, (Iceland) can lead to cooler temperatures in the mountain’s vicinity because of the ash in the atmosphere. The amount of solar energy reaching the surface is reduced by the ash plume, just like a cloud would do, resulting in a cooler temperature. The resulting daytime high temperatures can be reduced by several degrees when compared to near-by areas unaffected by the ash.