Looking for connections: Greg Lehn and the changing climate in the Arctic

It was quite a busy summer and fall for EPS graduate student, Greg Lehn.  In July, he traveled to the U.S. Army Cold Regions Research and Engineering Lab (CRREL), in Fairbanks, Alaska.  While he was there, Greg sliced and processed the frozen permafrost soil cores he and collaborators have collected over the past two summers from watersheds on the North Slope of Alaska.  He then analyzed the elemental and isotope (Ca and Sr) composition of soil and soil water.

Why the interest in permafrost soils?  Permafrost soils have high carbon content. The top three meters of permafrost contain anywhere between as much to twice as much carbon as found in the atmosphere. If the climate continues to warm, the carbon stored in permafrost could be released as carbon dioxide and methane_, making the planet a warmer place.

Greg’s goal was to monitor and predict the fate of this soil carbon with Ca isotopes.  By taking advantage of CaCO₃ gradients in soils on the North Slope of Alaska and the seasonal thaw of permafrost, Greg hoped to use Ca as a geochemical tracer of permafrost thaw depth.  This proxy will reveal connections between soil processes related to climate change and the carbon export from Arctic permafrost soils

Greg’s research was supported by an NSF grant awarded to his Ph.D. supervisor, Prof. Andrew Jacobson, and an EPA Star Graduate Fellowship, which Greg received last year.  During the fall, Greg attended the EPA Star Grant Fellowship meeting in Washington D.C. where he presented a poster of his initial findings, attended professional development sessions and networked with other STAR fellowship awardees.