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Harvard Forest Data Archive

HF214

Fluxes of Carbonyl Sulfide at Harvard Forest EMS Tower since 2010

Related Publications

Data

  • hf214-01: carbonyl sulfide flux in 2011 using the prototype OCS spectrometer (preview)
  • hf214-02: carbonyl sulfide flux in 2012-2013 using the 2nd-generation OCS spectrometer (preview)
  • hf214-03: ocs profiles in 2012-2013 (preview)

Overview

  • Lead: Roisin Commane, Steven Wofsy, Richard Wehr
  • Investigators:
  • Contact: Roisin Commane
  • Start date: 2010
  • End date: 2013
  • Status: completed
  • Location: Prospect Hill Tract (Harvard Forest)
  • Latitude: +42.537755
  • Longitude: -72.171478
  • Elevation: 340 meter
  • Taxa:
  • Release date: 2016
  • Revisions:
  • EML file: knb-lter-hfr.214.9
  • DOI: digital object identifier
  • Related links:
  • Study type: long-term measurement
  • Research topic: forest-atmosphere exchange
  • LTER core area: primary production, inorganic nutrients
  • Keywords: biogeochemistry, eddy covariance, sulfide
  • Abstract:

    Carbonyl sulfide (OCS), the most abundant sulfur compound in the atmosphere, controls the sulfur budget and aerosol loading of the stratosphere in times of low volcanic activity. OCS is also closely tied to the vegetative carbon cycle and may provide an independent measure of the photosynthetic uptake of carbon. However, the detailed nature of the biogeochemical cycling of OCS throughout the seasons in terrestrial ecosystems has not been thoroughly explored. We measured the seasonal response of the ecosystem flux of OCS above a deciduous temperate forest using an infrared laser absorption spectrometer at Harvard Forest (MA, USA) in 2011. Fluxes were calculated using two complementary approaches: gradient – flux (also known as flux – gradient; January – July, 2011) and eddy covariance flux (August – December, 2011), which agreed within the combined error for a period with both measurements. Strong uptake of OCS by the forest was observed during most of the growing season, but significant uptake also occurred when the deciduous leaves were not present. A strong diel cycle of mid-day OCS uptake was observed in May/June and August/September, consistent with OCS uptake by processes parallel to CO2 photosynthetic uptake, at the ecosystem scale, for these months. The results show that while overall OCS and CO2 both show evidence of vegetative uptake, the OCS flux cannot be explained by this process alone and the relationship between OCS and CO2 changes throughout the year above this mixed deciduous forest. The data imply that terrestrial uptake of OCS, and hence the stratospheric sulfur cycle, are potentially quite sensitive to extremes in temperature and soil moisture.

  • Methods:

    Prototype OCS Spectrometer

    OCS and CO2 were measured using a Tunable Infra-red Laser Direct Absorption Spectrometer (TILDAS, Aerodyne Research Inc.). OCS fluxes were measured by eddy covariance and gradient fluxes.

    2nd Generation OCS Spectrometer

    OCS, CO2, and meteorological data were collected during deployment of the 2nd-generation OCS quantum cascade laser spectrometer at the HF-EMS tower (years 2012 and 2013). Fluxes for which the sonic anemometer data were erroneous have been excluded. The CO2 and temperature cospectra used to correct for high-frequency signal attenuation are found in Harvard Forest Data Archive HF209. The OCS spectrometer sampled the same gas flow as the CO2 isotope spectrometer in record HF209, in series, and should be subject to the same tube-transit signal attenuation. The CO2 fluxes are from Harvard Forest Data Archive record HF209. The data for air temperature, pressure, relative humidity, dry air concentration, and PAR are from Harvard Forest Data Archive record HF004.

    OCS Profiles

    OCS and CO2 molar mixing ratios (to dry air) were measured at the indicated heights on the EMS flux tower by the 2nd-generation OCS quantum cascade laser spectrometer at the HF-EMS tower (years 2012 and 2013).

  • Use:

    This dataset is released to the public under Creative Commons license CC BY (Attribution). Please keep the designated contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement.

  • Citation:

    Commane R, Wofsy S, Wehr R. 2016. Fluxes of Carbonyl Sulfide at Harvard Forest EMS Tower since 2010. Harvard Forest Data Archive: HF214.

Detailed Metadata

hf214-01: carbonyl sulfide flux in 2011 using the prototype OCS spectrometer

  1. datetime: date and time stamp, mean value for the eddy flux integration period
  2. year: fraction of year (Eastern standard time, EST) (unit: nominalYear / missing value: NA)
  3. jd.1970: day of year since 1970 (R notation), EST (unit: nominalDay / missing value: NA)
  4. doy: day of year (unit: nominalDay / missing value: NA)
  5. doy.2011: fraction of day of year in 2011, EST (unit: nominalDay / missing value: NA)
  6. ocs.flux: flux of carbonyl sulfide (OCS, unit: pmol m-2 s-1) (unit: picomolePerMeterSquaredPerSecond / missing value: NA)
  7. eddy.flux.flag: valid data flag
    • 0: OCS flux not calculated by eddy covariance
    • 1: OCS flux calculated by eddy covariance
  8. grad.flux.flag: valid data flag
    • 0: OCS flux not calculated by the gradient flux method
    • 1: OCS flux calculated by the gradient flux method
  9. ocs.mr: mixing ratio of carbonyl sulfide (OCS; unit: pmol mol-1) (unit: dimensionless / missing value: NA)
  10. grad.flux.dz: distance between sampling points in gradient method (unit: meter / missing value: NA)

hf214-02: carbonyl sulfide flux in 2012-2013 using the 2nd-generation OCS spectrometer

  1. datetime: date and time stamp, mean value for the eddy flux integration period
  2. igor.time: redundant date and time stamp, used by the Igor programming language (seconds since the start of January 1, 1904) (unit: second / missing value: NA)
  3. eddy.flux.co2: CO2 eddy flux past the sensor at 29m (umol/m2/s), corrected for high frequency signal attenuation by comparison of the CO2 and temperature cospectra (unit: micromolePerMeterSquaredPerSecond / missing value: NA)
  4. eddy.flux.ocs: OCS eddy flux past the sensor at 29m (pmol/m2/s), corrected for high frequency signal attenuation by comparison of the CO2 (not OCS) and temperature cospectra (unit: picomolePerMeterSquaredPerSecond / missing value: NA)
  5. stor.flux.co2: CO2 storage flux, i.e. the increase in CO2 storage below 29m (unit: micromolePerMeterSquaredPerSecond / missing value: NA)
  6. stor.flux.ocs: OCS storage flux, i.e. the increase in OCS storage below 29m (unit: picomolePerMeterSquaredPerSecond / missing value: NA)
  7. heat.flux: sensible heat flux past the sensor at 29m (unit: wattPerMeterSquared / missing value: NA)
  8. airt: air temperature (unit: celsius / missing value: NA)
  9. airp: air pressure (unit: millibar / missing value: NA)
  10. rh: relative humidity (unit: dimensionless / missing value: NA)
  11. dry.air: concentration of dry air (unit: molePerCubicMeter / missing value: NA)
  12. par: photosynthetically active radiation (unit: micromolePerMeterSquaredPerSecond / missing value: NA)
  13. wind.speed: mean wind speed (unit: metersPerSecond / missing value: NA)
  14. wind.dir: mean wind speed (degrees from north) (unit: degree / missing value: NA)
  15. ustar: friction velocity (unit: metersPerSecond / missing value: NA)
  16. co2: mean CO2 molar mixing ratio to dry air (parts per million) (unit: dimensionless / missing value: NA)
  17. ocs: mean OCS molar mixing ratio to dry air (parts per trillion) (unit: dimensionless / missing value: NA)
  18. bad.zero: instrument zero reading flag
    • 1: instrument zero reading was in error
    • 0: instrument zero reading was ok
  19. bad.data: instrument data flag
    • 1: instrument data were completely bad
    • 0: instrument data were ok (aside from possible error in the zero level)
  20. ocs.corr: instrument spectral background correction flag
    • 1: instrument spectral background was successfully corrected in post-processing
    • 0: instrument spectral background was not successfully corrected in post-processing

hf214-03: ocs profiles in 2012-2013

  1. datetime: date and time stamp, mean value for the first inlet, i.e. the inlet closest to the ground; add 1 min for each subsequent inlet, i.e. add 3 min to obtain the mean time for the inlet at 12.5m
  2. igor.time: redundant date and time stamp, used by the Igor programming language (seconds since the start of January 1, 1904) (unit: second / missing value: NA)
  3. num.inlets: number of sampling inlets active (unit: number / missing value: NA)
  4. co2.0.2m: CO2 molar mixing ratio to dry air measured at 0.2m (parts per million) (unit: dimensionless / missing value: NA)
  5. co2.1.0m: CO2 molar mixing ratio to dry air measured at 1.0m (parts per million) (unit: dimensionless / missing value: NA)
  6. co2.7.5m: CO2 molar mixing ratio to dry air measured at 7.5m (parts per million) (unit: dimensionless / missing value: NA)
  7. co2.12.5m: CO2 molar mixing ratio to dry air measured at 12.5m (parts per million) (unit: dimensionless / missing value: NA)
  8. co2.18.3m: CO2 molar mixing ratio to dry air measured at 18.3m (parts per million) (unit: dimensionless / missing value: NA)
  9. co2.24.1m: CO2 molar mixing ratio to dry air measured at 24.1m (parts per million) (unit: dimensionless / missing value: NA)
  10. co2.29.0m: CO2 molar mixing ratio to dry air measured at 29.0m (parts per million) (unit: dimensionless / missing value: NA)
  11. ocs.0.2m: OCS molar mixing ratio to dry air measured at 0.2m (parts per trillion) (unit: dimensionless / missing value: NA)
  12. ocs.1.0m: OCS molar mixing ratio to dry air measured at 1.0m (parts per trillion) (unit: dimensionless / missing value: NA)
  13. ocs.7.5m: OCS molar mixing ratio to dry air measured at 7.5m (parts per trillion) (unit: dimensionless / missing value: NA)
  14. ocs.12.5m: OCS molar mixing ratio to dry air measured at 12.5m (parts per trillion) (unit: dimensionless / missing value: NA)
  15. ocs.18.3m: OCS molar mixing ratio to dry air measured at 18.3m (parts per trillion) (unit: dimensionless / missing value: NA)
  16. ocs.24.1m: OCS molar mixing ratio to dry air measured at 24.1m (parts per trillion) (unit: dimensionless / missing value: NA)
  17. ocs.29.0m: OCS molar mixing ratio to dry air measured at 29.0m (parts per trillion) (unit: dimensionless / missing value: NA)
  18. bad.zero: instrument zero reading flag
    • 1: instrument zero reading was in error
    • 0: instrument zero reading was ok
  19. bad.data: instrument data flag
    • 1: instrument data were completely bad
    • 0: instrument data were ok (aside from possible error in the zero level)
  20. ocs.corr: instrument spectral background correction flag
    • 1: instrument spectral background was successfully corrected in post-processing
    • 0: instrument spectral background was not successfully corrected in post-processing