The impacts of changes in snowfall on soil greenhouse gas emissions using an automated chamber system.

Ruan L., K. Kahmark, and G.P. Robertson.

Presented at the All Scientist Meeting (2013-04-04 to 2013-04-05 )

1. The feedback effect of global warming itself impacts emissions of Greenhouse Gas (GHG) from biogenic sources such as agricultural systems.

2. Snow cover has decreased in many regions of the northern hemisphere and is projected to decrease further in most. The reduced snow cover may enhance soil freezing and increase the depth of frost. The frequency of freeze-thaw cycles is likely to increase due to the reduction of snowpack thickness.

3. Freeze and thaw cycles can strongly affect soil C and N dynamics. The pulses of N2O emissions from soil after thawing have been reported in various studies. However, most studies were based on the controlled laboratory conditions or low resolution static chamber methods in situ.

4. Near-continuous automated chambers provide the temporal resolution needed for capturing short-lived pulses of greenhouse gases after intermittent melting events.