Greenhouse Gas Source Attribution

Anthropogenic greenhouse gas (GHG) emissions are predominantly attributable to combustion. Fossil-fuel combustion is responsible for 80 percent of anthropogenic GHG emissions and 98 percent of anthropogenic CO2 emissions. Approximately 60 percent of anthropogenic CO2 emissions are from the use of transportation fuels. In order to address the need for methods to identify and characterize GHG emission sources, we have developed and deployed a mobile laboratory facility for measuring GHGs and co-emitted tracers of their anthropogenic and biogenic sources. Our mobile facility includes two 30-foot-long trucks, a temperature-controlled trailer, and a suite of in situ and remote sensing instruments. The payload is designed for developing methodologies for climate treaty verification, municipal GHG emissions mitigation policy support, and carbon-cycle science and includes the following:

  • a high-precision, fast CO2 isotope analyzer for measuring abundances and fluxes of 12C16O2, 13C16O2, 12C16O18O, and H2O via multipass absorption of emission from a quantum-cascade laser near 4.32 µm (Aerodyne Research);
  • a gas analyzer for measuring CO2, CH4, and H2O using cavity-ringdown spectrometry (Picarro);
  • a high-sensitivity proton-transfer reaction mass spectrometer for measuring volatile organic compounds (Ionicon Analytik Gesellschaft);
  • a drum sampler for determining elemental particle composition (Streetman Precision Engineering);
  • a condensation particle counter (TSI);
  • an AirCore system for sampling aloft (Restek);
  • a UV-absorption instrument for measuring O3 (Ecotech);
  • an filter-based IR absorption instrument for measuring CO (Ecotech);
  • a chemiluminescence instrument for measuring NOx (Ecotech);
  • a UV-fluorescence instrument for measuring SO2 (Ecotech);
  • a nondispersive infrared absorption CO2 analyzer (LI-COR);
  • a 3D sonic anemometer for measuring wind speed and direction (Gill);
  • a thermal sensor for measuring soil fluxes (Hukseflux);
  • soil temperature probes and temperature and relative humidity sensors (Campbell Scientific);
  • a solar-viewing Fourier transform infrared (1–15 µm) spectrometer for measuring multiple chemical species (ABB-Bomem);
  • a multiwavelength robotic sun-photometer for measuring aerosols (AERONET/CIMEL);
  • a total sky imager for measuring cloud cover (Yankee Environmental Systems); and
  • a lidar ceilometer for determining boundary layer height (Vaisala).

Additional instruments owned by collaborating labs include

  • an automated flask-sampling system to collect air samples for 14C analysis (NOAA)1;
  • a gas analyzer for measuring CO2, CH4, and H2O using cavity-ringdown spectrometry (Picarro)1;
  • a gas analyzer for measuring CO2, H2O, and d13C-CO2 using cavity-ringdown spectrometry (Picarro)1;
  • a photoacoustic aerosol spectrometer (Droplet Measurement Technology)2; and
  • a water (vapor and liquid) stable O, H isotope analyzer using cavity-ringdown spectrometery (Piacarro)2.

1Lawrence Livermore National Laboratory; 2Los Alamos National Laboratory

Measurements from these instruments are coupled with inverse modeling and uncertainty quantification techniques to identify and characterize anthropogenic and biogenic GHG sources and sinks. We are also developing new instruments and augmenting existing equipment to expand technology for tracer measurements.