Wednesday, November 5, 2014
Quality Carbon Cycle Measurements Continue…
The NGEE Arctic team is committed to collecting quality datasets that can, in turn, provide knowledge to inform climate models. We are doing this for several disciplines including hydrology, biogeochemistry, and vegetation dynamics. One area where we are especially focused is on the measurement CO2 and CH4 flux from polygonal landscapes on the North Slope of Alaska. These two greenhouse gases, both products of thawing and degrading permafrost, are important inputs to the atmosphere that determine the rate and magnitude of future warming of the planet.
Today our team left the Building 142 staging area a few miles east of Barrow and traveled to our field site using snow machines. John used a Topcon dGPS to identify locations for our measurements. He will eventually locate 65 to 70 sites buried beneath 10 to 50 cm of snow, but today John focused on plots along the 65-meter long tram. PVC collars had been installed along the tram earlier in the year and project scientists have been measuring CO2 and CH4 flux routinely throughout the year. Once identified, the collars were gently cleaned and an LGR system was used to measure fluxes per unit ground area over a few minute period. Ori and Naama were able to take all the measurements within a few hours of admittedly limited daylight. It was surprising that despite snow, frozen ground, and ice we were still able to measure positive, albeit low, fluxes for both CO2 and CH4. It will take a few weeks to analyze the data but these final measurements should complete what has been a rewarding and successful 2014 field campaign.
John continues to locate other sites where we will conduct similar measurements tomorrow. We will also be collecting samples of air from stainless steel “gas wells” that had been previously inserted into the active layer.