NOAAGHG

SGP Air Sampling for GHGs

1 May 2025 - 30 April 2027

Lead Scientist: John Miller

Observatory: SGP (Southern Great Plains)

NOAA's Global Monitoring Laboratory (GML) maintains the world’s largest network of air sampling for high precision measurements of greenhouse gases.  The DOE/ARM Southern Great Plains (SGP) site has historically been an important component of this network, because it helps represents the interior of the U.S.  Among other characteristics, air samples collected at this site show sensitivity to both regional-scale ecosystem fluxes of CO2, N2O, and CH4, as well as influence of anthropogenic emissions such as those from oil and gas extraction activities. Additional measurements of related tracers such as CO and the stable and radio-isotopes of carbon in CO2 help us partition the natural and anthropogenic influences on the observed GHG variations. The primary use of the SGP GHG data will be to act as important constraints on south-central/western US GHG fluxes within the global CarbonTracker-CO2 and CarbonTracker-CH4 global data assimilation systems that NOAA/GML operates.

The air sampling plan will closely follow the past history of air sampling at SGP, that was previously performed in cooperation with ARM and LBNL (Sebastien Biraud, PI).  Two complimentary modes of sampling will be employed: 1) Largely automated sampling of air approximately 3-4 times per week using a Programmable Flask Package (PFP) and Portable Compressor Package (PCP), and 2) Semi-automatic automatic air sampling on a weekly basis using a Portable Sampling Unit (PSU).  In both cases air will be sampled into boro-silicate (glass) flasks and shipped to NOAA/GML in Boulder, CO for laboratory analysis of various mixing and isotopic ratios.  For PFP sampling, only the PFP suitcase is shipped back and forth, with the PCP remaining at the site.  For the PFP sampling, a high-performance air drier is also used.  For the PSU sampling, a smaller drier is built into the unit.