When an event is big enough that it cancels airplane flights for nearly a week and draws daily worldwide attention, it is going to spawn rumors and discussion. One such rumor coming out of the volcanic eruption in Iceland about 10 days ago is that it will affect weather patterns.
Ken Scheeringa, associate state climatologist in Indiana, says that statement is true as far as it goes. However, it needs to be clarified. What's happened so far with the first eruption of the volcano in Iceland is probably enough impact to affect weather patterns in Europe, he says. However, it was not strong enough and didn't send ash high enough to affect weather patterns around the globe, including here in the U.S.
The ash plume was only about 5 miles high, Scheeringa reports. That won't carry ash worldwide. Instead, it takes plumes 10 miles high that reach into the stratosphere to affect an entire hemisphere.
There is precedent for that happening, Scheeringa says. Perhaps the best recent example, he notes, is the eruption of Mt. Pinatubo in 1992. There were frosts in Indiana in June fo that year. Some of the frost pockets were strong enough to kill corn. Purple, dying corn leaves from a frost in mid-June is not something you soon forget. While other factors were involved in helping determine when and if the frost happened, Scheeringa believes the volcanic eruption helped set the stage for that event.
The problem in 1992 was dimmed sunshine throughout the summer, he recalls. Sunrises and sunsets were brilliant, he remembers, and says it happened because of scattered sunlight, compared to normal conditions. The impacts don't last only one season, either, from something that enormous. Instead, an event that large can impact weather for more than one season.
That season featured jacket weather in July, and a huge, wet corn crop. Although last season's outcome of a huge, wet corn crop was traced to late planting, not volcanic activity, cool weather along the way, especially in July in both instances, added to how the crop developed during the summer.
The bottom line is that you don't need to worry about what the mid-April volcanic eruption will due to weather unless you're planning a holiday in Europe. Otherwise, there should be no impact here, the climatologist concludes.