Precision Gas Sampling (PGS) Validation2011-2014 Final Campaign Report

Tom, M. S.²  Fischer, M. L.²  Biraud, S. C.²  Billesbach, D.³ 

[1]Pacific Northwest National Laboratory

[2]Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

[3]Univ. of Nebraska, Lincoln, NE (United States)

DOI  :  10.2172/1236603
RP-ID  :  DOE/SC-ARM--15-028
PID  :  OSTI ID: 1236603

美国|英语

来源: SciTech Connect

【 摘 要 】

In this field campaign, we used eddy covariance towers to quantify carbon, water, and energy fluxes from a pasture and a wheat field that were converted to switchgrass. The U.S. Department of Energy is investing in switchgrass as a cellulosic bioenergy crop, but there is little data available that could be used to develop or test land surface model representations of the crop. This campaign was a collaboration between Lawrence Berkeley National Laboratory and the U.S. Department of Agriculture Agricultural Research Service. Unfortunately, in 2011, Oklahoma had one of the most severe droughts on record, and the crop in one of the switchgrass fields experienced almost complete die-off. The crop was replanted, but subsequent drought conditions prevented its establishment. Then, in April 2012, a large tornado demolished the instruments at our site in Woodward, Oklahoma. These two events meant that we have some interesting data on land response to extreme weather; however, we were not able to collect continuous data for annual sums as originally intended. We did observe that, because of the drought, the net ecosystem exchange of CO₂ was much lower in 2011 than in 2010. Concomitantly, sensible heat fluxes increased and latent heat fluxes decreased. These conditions would have large consequences for land surface forcing of convection. Data from all years were submitted to the Atmospheric Radiation Measurement Climate Research Facility Data Archive, and the sites were registered in AmeriFlux.