@article{26421,
  author = {Arlyn E Andrews and Jonathan D Kofler and Michael E Trudeau and Jonathan C Williams and Don H Neff and Kenneth A Masarie and Danlei Y Chao and Duane R Kitzis and Paul C Novelli and Conglong Zhao and Edward J Dlugokencky and Patricia M Lang and Molly J Crotwell and Marc L Fischer and Matthew J Parker and John T Lee and Daniel D Baumann and Ankur R Desai and Charles O Stanier and Stephan F. J De Wekker and Daniel E Wolfe and William J Munger and Pieter P Tans},
  title = {CO<sub>2</sub>, CO, and CH<sub>4</sub> measurements from tall towers in the NOAA Earth System Research Laboratory's Global Greenhouse Gas Reference Network},
  abstract = {<p>A reliable and precise in situ CO<sub>2</sub> and CO analysis system has been developed and deployed at eight sites in the NOAA Earth System Research Laboratory's (ESRL) Global Greenhouse Gas Reference Network. The network uses very tall (&gt; 300 m) television and radio transmitter towers that provide a convenient platform for mid-boundary-layer trace-gas sampling. Each analyzer has three sample inlets for profile sampling, and a complete vertical profile is obtained every 15 min. The instrument suite at one site has been augmented with a cavity ring-down spectrometer for measuring CO<sub>2</sub> and CH<sub>4</sub>. The long-term stability of the systems in the field is typically better than 0.1 ppm for CO<sub>2</sub>, 6 ppb for CO, and 0.5 ppb for CH<sub>4</sub>, as determined from repeated standard gas measurements. The instrumentation is fully automated and includes sensors for measuring a variety of status parameters, such as temperatures, pressures, and flow rates, that are inputs for automated alerts and quality control algorithms. Detailed and time-dependent uncertainty estimates have been constructed for all of the gases, and the uncertainty framework could be readily adapted to other species or analysis systems. The design emphasizes use of off-the-shelf parts and modularity to facilitate network operations and ease of maintenance. The systems report high-quality data with &gt; 93% uptime. Recurrent problems and limitations of the current system are discussed along with general recommendations for high-accuracy trace-gas monitoring. The network is a key component of the North American Carbon Program and a useful model for future research-grade operational greenhouse gas monitoring efforts.</p>},
  year = {2014},
  journal = {Atmospheric Measurement Techniques},
  volume = {7},
  pages = {647-687},
  doi = {10.5194/amt-7-647-2014},
  note = {<p>Complete title:</p><p>CO<sub>2</sub>, CO, and CH<sub>4</sub> measurements from tall towers in the NOAA Earth System Research Laboratory's Global Greenhouse Gas Reference Network: instrumentation, uncertainty analysis, and recommendations for future high-accuracy greenhouse gas monitoring efforts</p>},
}