A twelve-station tower-based observation network measuring CO 2 , CH 4 , and CO was deployed in and around the Indianapolis, IN metropolitan area as part of the Indianapolis Flux Experiment (INFLUX). Measurements began in 2010 and the full network was deployed by 2013. Observations were made at heights ranging from 39 to 136 m above ground level using existing communication towers. Several towers in the network had multiple measurement levels. Cavity ring-down spectrometers (CRDS) were used at all twelve sites and at least one calibrated reference tank was sampled daily at each site. Real time data communications were performed via cellular modems and data were transmitted daily for processing and quality assurance checks. Data quality control procedures were utilized to ensure compatibility within the INFLUX tower network and with global standards. For example, field target/calibration tanks were used to detect long-term instrument drift and instrument failure. Network-wide round robin tests were performed every 1–2 years to detect possible target tank drift and ensure network-wide comparability between measurements. NOAA flask packages were deployed at six of the INFLUX towers to provide a flask to in-situ direct comparison of the atmospheric samples. Results from these activities demonstrate that the compatibility of the CO 2 , CH 4 , and CO INFLUX in-situ tower-based measurements are less than or equal to 0.18 ppm CO 2 , 1.0 ppb for CH 4 , and 6 ppb for CO.
All Science Journal Classification (ASJC) codes
- Environmental Engineering
- Geotechnical Engineering and Engineering Geology
- Atmospheric Science