Description: Purdue Aircraft data

TITLE:  Aircraft-based CO2 and CH4 measurements from the city of Indianapolis, IN, USA

PROJECT:  Indianapolis Flux Experiment (INFLUX)

DATES:  Flight experiments in 2011:  01 March, 29 April, 01 June, 30 June, 12 July, and 18 August

ABSTRACT:  Urban environments are responsible for more than 70% of energy related global fossil fuel emissions, and this figure is expected to increase as cities continue to expand and grow in the coming decades.  Measurement approaches must be in place to verify compliance to future control and mitigation strategies.  The Indianapolis Flux experiment (INFLUX) is a collaborative effort that aims to develop, assess and improve methods for quantifying urban greenhouse gas emissions, focusing on the city of Indianapolis.  Data posted in this site correspond to several 2011 flight experiments in the air shed of Indianapolis to quantify the anthropogenic CO2 and CH4 enhancement downwind of the city.  Using these data and an aircraft-based mass balance approach (Mays et al., 2009), we quantify the citywide CO2 and CH4 emission flux of Indianapolis, assess the uncertainties of the method, and suggest improvements in the experimental flight plan to minimize these uncertainties (Cambaliza et al., 2013).

For November-December 2014 only, CO was added to the list of measurements. Uncalibrated CO is given in ppm.

COMMENTS:  Concentrations of CO2, CH4 and H2O were measured at a frequency of 0.5 Hz using an in-situ flight-ready Picarro cavity ring-down spectrometer (CRDS) model number G2301-f.  In-flight calibrations were performed for all flight experiments using three NOAA/ESRL calibration standards.  Flight coordinates (latitude, longitude, height above mean sea level) were measured at 50 Hz using a global positioning and inertial navigation system.  Atmospheric pressure, wind speed and wind direction were also measured at 50 Hz using a Best Air Turbulence (BAT) probe (Garman et al., 2006).   At the center of the BAT probe hemisphere is a microbead thermistor for ambient temperature (50 Hz) measurements.


Cambaliza, M.O., Shepson, P. B., Caulton, D., Stirm, B., Samarov, D., Gurney, K., Turnbull, J., Davis, K. J. Possolo, A., Karion, A., Sweeney, C., Moser, B., Hendricks, A., Lauvaux, T., Mays, K., Whetstone, J., Huang, J., Razlivanov, I., Miles, N. L., and Richardson, S., J.:  Assessment of uncertainties of an aircraft-based mass-balanced approach for quantifying urban greenhouse gas emissions, Atmos. Chem. Phys. Discuss., 13, 1 – 51, 2013.

Garman, K. E., Hill, K. A., and Wyss, P., Carlsen, M., Zimmerman, J. R., Stirm, B. H., Carney, T. Q., Santini, R., and Shepson, P. B.:  An airborne and wind tunnel evaluation of a wind turbulence measurement system for aircraft-based flux measurements, J. Atmos. Oceanic Technol., 23, 1696 – 1708, 2006.

Mays, K. L., Shepson, P. B., Stirm, B. H., Karion, A., Sweeney, C., and Gurney, K. R.:  Aircraft-based Measurements of the Carbon Footprint of Indianapolis, Environ. Sci. Technol., 43, 7816-7823, 2009.

COLUMN HEADERS:  GMT (Date and Time in GMT, with fractional seconds), Latitude (degrees), Longitude (degrees), HeightAbvMSL (Height above Mean Sea Level, meters), CO2 (dry mole fraction, ppm), CH4 (dry mole fraction, ppm), H2O (mole fraction, percent), Ps (pressure, mbars), Temp (temperature, Kelvin), WS (wind speed, ms-1), WD (wind direction, degrees)

FAIR USE POLICY:  Permission to download the data does not grant permission to use the information contained therein for publication or commercial use.  Please request permission for such use by sending an email before any commercial use or publication.  Questions about the use of these data or the Fair Use policy can be directed to Paul Shepson at

To access the data, please go to the PSU Data Commons, keyword INFLUX. Please contact the below contact and inform them of your intended use and publication plans (if any), and so we have your contact in case of changes to the dataset.  Thanks!


Paul Shepson (
Department of Chemistry
Purdue University
West Lafayette, IN 47907
765 – 496 – 2414



(last updated 06 December 2013)

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