In-situ tower data

TITLE:  In-situ tower greenhouse gas data (The Pennsylvania State University)
PROJECT:  Marcellus Methane
DATES:  May 2015 – February 2017 (for East, Central, and North sites)
May 2015 – current for South site


Quantification of regional emissions resulting from natural gas extraction activities is critical in terms of determining the climate effects of natural gas usage compared to coal.  The leakage rate is not well known, and has large implications for the greenhouse impact of this energy source.   Towards that end data were collected at four towers in the Marcellus Shale gas region, with a tower south of the primary natural gas extraction region serving as a background site.  Cavity ring down spectrometer (CRDS, Picarro, Inc, G2132-i) measurements of  CH4 and CO2 mole fractions, and the isotopic ratio of CH4, are collected at these tower sites at heights of between 46 and 61 m above ground level.   The sample air stream is dried using a Nafion dryer.  The laboratory and field calibration technique is described in Miles et al., (citation below).  Flask to in-situ comparisons indicate mean differences of 2+-2 ppb CH4, 0.2+-0.4 ppm CO2, and 0.0+-0.4 permil at the South tower.  Ten-minute averages are reported here, with the minimum and maximum time included in the average indicated.

COLUMN HEADERS (processed data):  Site name, Height (m AGL), Time (minimum fractional day of year of the measurement, GMT), Time (maximum fractional day of year of the measurement, GMT), Year, DOY (day of year), Hour (GMT), CO2 (dry mole fraction, ppm), Standard_Deviation (during measurement, ppm), CH4(dry mole fraction, ppb), Standard_Deviation (during measurement, ppb), isotopic ratio (13C/12C, permil), number of points included in average, Flag, H2O(percent)

COLUMN HEADERS (raw data):  DATE, TIME, FRAC_DAYS_SINCE_JAN1, FRAC_HRS_SINCE_JAN1, JULIAN_DAYS, EPOCH_TIME, ALARM_STATUS,              INST_STATUS, CavityPressure, CavityTemp, WarmBoxTemp, EtalonTemp, DasTemp, MPVPosition, solenoid_valvess, OutletValve, species, 13CH4, H2O, CO2, Delta_iCH4_Raw,            HP_12CH4, HP_Delta_iCH4_2min, HP_Delta_iCH4_30s, HP_Delta_iCH4_5min, HP_Delta_iCH4_Raw, HR_12CH4, HR_Delta_iCH4_2min, HR_Delta_iCH4_30s, HR_Delta_iCH4_5min , HR_Delta_iCH4_Raw, ChemDetect, HC_base_offset_diff, HC_slope_offset_diff, HC_res_diff, peakheight_5, peak0_spec, ch4_splinemax, peak30_spec, peak24_spec, peak_24, peak_30, PPF_res, PPF_base_offset, PPF_slope_offset, PPF_shift, PPF_CH4_conc, PPF_H2O_conc, PPF_C2H6_conc, PPF_C2H4_conc, PPF_NH3_conc, PPF_H2S_conc

We reserve the right to make corrections to the data based on scientific grounds, e.g., recalibration of standard gases or discovery of operational issues not known at the time of the release.  If the data are obtained for potential use in a publication or presentation, kindly inform Penn State personnel ( of the nature of this work.


  • Miles, N.L., D.K. Martins, S.J. Richardson, C. Rella, T. Lauvaux, K.J. Davis, Z.R. Barkley, K. McKain, and C. Sweeney. Calibration and field testing of cavity ring-down laser spectrometers measuring CH4, CO2, and δ13CH4 deployed on towers in the Marcellus Shale region. Meas. Tech. Disc., in review,, 2017.
  • Miles, N.L., D.K. Martins, S.J. Richardson, T. Lauvaux, K.J. Davis, B.J. Haupt, and C. Rella, 2017. In-situ tower atmospheric methane mole fraction and isotopic ratio of methane data, Marcellus Shale Gas Region, Pennsylvania, USA, 2015-2016. Data set. Available on-line [] from The Pennsylvania State University Data Commons, University Park, Pennsylvania, USA.

FLAGS:  1 indicates no known problems. 0 indicates that the data is unavailable or not recommended for use. 7 indicates that there were instrument problems of some kind, but the averaged data appears to be good quality. Use with caution. 9 indicates that there were no known instrument problems, but data is unrealistic compared to other sites and is not recommended for use.

2015: mole fractions only, no calibrated isotopic ratios
Extended outages:
CENTRAL 2016 DOY 153-217 no data
CENTRAL 2016 DOY 218-355 no isotopic ratio
NORTH 2016 DOY 157-216 no data

To access the data, please go to the PSU Data Commons, keyword Marcellus. Thanks!

Natasha Miles (
Scott Richardson (