Iowa topsoil impacts summertime temperatures
November 26th, 2012 by Ric Hanson
An Iowa State University scientist says if this coming spring is dry, record high temperatures are likely for the summer of 2013. Christopher Anderson is the assistant director of Iowa State University’s climate science program.”Our recent history tells us what can be predicted with certainty,” Anderson says. “Iowa’s wet years will become wetter and dry years will become drier (and) hotter.” Anderson says Iowa’s “deep, organic soils” help “modulate” the temperature in the summer — but only if the ground is moist. “In Iowa, wet springs lead to cool summers. It seems counter intuitive, but the reason is because of our great soils. Recent examples are 2008, 2010 and 2011,” Anderson says.
“In 2012, rainfall was much below normal and we didn’t have floods, but instead July temperatures ranked third highest in the 140-year record.” According to Anderson, the summertime “cooling mechanism” that Iowa’s soil provides when it’s moist may be altered, however, by more frequent springtime floods that sweep away the topsoil. “The clearest trend that we’re seeing in Iowa’s climate records is in the spring rainfall,” Anderson says. “Our spring rainfall is much higher than it has been in the 140-year record and so what happens when there’s more spring rainfall is there’s potential and there is actual soil loss and if we lose our soil, we lose this ability to keep ourselves cool in the summer.”
There are about 450 different types of soil in Iowa. The average depth of topsoil in Iowa is between six and eight inches.