Future of arctic may depend on permafrost

Oliver W. Frauenfeld, assistant professor in the Department of Geography at Texas A&M, and colleague Trent Ford of Southern Illinois University have had their work published in the current issue of Scientific Reports.

The researchers believe permafrost might be the hidden wild card that could determine the fate of Arctic regions.

Permafrost is permanently frozen soil found mainly in the polar regions. It occurs in areas in which the summer warmth fails to penetrate the ground enough to thaw out the soil. As a result of climate change, many areas of permafrost are at risk of thawing, the researchers say.

Permafrost is a major subsurface feature across the polar regions, and has been shown to impact moisture availability for groundwater and discharge. These new findings now also show that the presence or absence of permafrost is a key influence on high-latitude precipitation.

The researchers analyzed numerous data sources in high-latitude areas and found that permafrost conditions are directly tied to Arctic precipitation. They examined land and atmospheric data from 1979 to 2012 to determine patterns and trends in permafrost conditions across Eurasian high-latitude areas.

"We were able to establish a direct relationship between permafrost and summer rainfall in the Eurasian Arctic," Frauenfeld explains.

"Humidity, convection and rainfall have all been increasing in areas where there is continuous permafrost, but decreasing in areas where there is only patchy or no permafrost."

The researchers believe that whether the Arctic lands will turn into wetlands or drylands in the future because of declining permafrost is a big unknown in the scientific community.

"We think we are the first to directly link Arctic precipitation to permafrost," Frauenfeld adds.

"The study shows that where there is discontinuous or no permafrost at all, there will be a lower likelihood of rainfall. If permafrost degradation occurs, there is less precipitation and therefore this suggests that drying, or a 'drylands scenario,' will be the more likely outcome.

"The repercussions of this would be that the wetlands ecosystems that currently exist in the Arctic would disappear in the future, and that Arctic\polar deserts would expand.

"As climate change causes continuous permafrost to decline or disappear, this will likely alter the entire Arctic hydrologic cycle."