The Indianapolis Flux Experiment (INFLUX) was designed to develop and evaluate methods for the measurement and modeling of greenhouse gas fluxes from urban environments. Determination of greenhouse gas fluxes and uncertainty bounds is essential for the evaluation of the effectiveness of mitigation strategies.

The INFLUX observation network includes:

  • 12 in-situ tower-based, continuous measurements of CO2 (5 also measure CO and 5 measure CH4
  • Flask sampling of 14CO2 and other trace gases at 5 tower sites and in aircraft
  • Periodic aircraft sampling of greenhouse gases and meteorological conditions.
  • Total carbon column observing network (TCCON) column remote sensing station (Aug – Dec 2012)
  • Eddy covariance and radiative flux measurements for the purpose of model evaluation (coming in Sept 2013)
  • Scanning Doppler lidar used to determine 3-D wind fields and boundary layer depth

The data from the towers, TCCON, and aircraft measurements are being used in an inverse-modeling approach to yield estimates of the urban area flux at 1 km2 resolution.

Link to INFLUX ground-based instrumentation map

Additionally, very high space/time resolution estimates of fossil fuel carbon emissions (Hestia project) offer state-of-the-art “bottom up” emissions estimates for the city and its surroundings.

Objective: To develop and assess methods of quantifying greenhouse gas emissions at the urban scale, using Indianapolis as the test site.

Project Goals:

  • Develop better technique/approach for measurement of area-wide greenhouse gas emission fluxes.
  • Compare top-down emission estimates from aircraft and tower-based measurements with bottom-up emission estimates from Hestia for Indianapolis.
  • Quantify uncertainties in the measurements.
  • Utilize results to improve Hestia.


 Questions about INFLUX?  Please email us at co2data@meteo.psu.edu.


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