Volcanco affects weather

Inside Dakota Ag

Don’t like the weather? Wait a minute – for a volcano to erupt.

Published on: April 21, 2010

The weather across the Dakotas has been so nice lately that I’ve been waiting for it to change.

So when the volcano in Iceland erupted, I thought, “Here we go --the ash cloud will eventually get around the globe and block out sunlight, giving us another cool summer, the third one in a row.”

So I emailed Dennis Todey and Adrian Akyuz, climatologists for North Dakota and South Dakota, and Frank Watson, Dakota’s Farmer’s weather columnist, and asked them what they thought might happen.

And good news.

Watson replied, “The Iceland ash cloud should have no effect on our weather. The ash cloud is about 20,000 feet into the air. It needs to be up around 50,000 feet to have any affect. Most of the ash is washed out by showers.”

“My overall impression is that the volcano will have little impact here,” wrote Todey, “This is not a huge eruption as volcanoes go.  … the few [forecasts] I have seen seem to thin the plume out of the Asian Continent, leaving not much to get around to the U.S.  If it continues I suppose we could see a little impact with a little more color to sunsets.  But I don’t see a major impact to us at all. The times we see influences over us are with the major eruptions putting SO2 into the stratosphere, which in turn reflects incoming solar radiation and cools the globe for short periods (see Pinatubo in 1991, Krakatoa, Tambora in the 1800s).  This is not on that scale at all.”

However, Adrian Akyuz said it may be too early to tell how the Icelandic eruption might affect Dakota weather, because the eruption isn't over.

“When Mt. Pinatubo erupted in June 1991 in Philippines, it changed the Global Climate. Injection was so powerful, ash remained in Stratosphere (layer Between 11 to 50 km) the following year reducing the incoming solar radiation 10% globally which in turn reduced the global annual average temperature by 0.5°C in 1992. Also It produced 2 coolest years (1991 and 1992) in the 1990s. If Icelandic eruption continues to deposit ash into the atmosphere, it can be ejected in stratosphere where it can travel at high speeds to disperse the entire northern hemisphere. Depending on the density of the dispersion, it can impact our weather here in North Dakota. … However, we have to realize that Mt. Pinatubo ejected 20 million tons of Sulfur Dioxide (more than twice than El Chichon in Mexico). It is too early to speculate what will happen.”

I emailed Mark Seely, University of Minnesota’s climatologist, and though he didn’t reply in time to be included in this dispatch, I saw on his website that the National Weather Service has predicted another cool growing season for the region.

Maybe that change in the weather is coming anyway.