Atmospheric methane and carbon dioxide and surface water methane from the SWERUS-C3 Arctic Ocean expedition in 2014, leg 1

Brett Thornton, Marc Geibel, Patrick Crill, Christoph Humborg

Atmospheric observations of CH₄ and CO₂ above the Eastern Arctic Ocean, and dissolved CH₄ in surface waters of the Eastern Arctic Ocean in July and August 2014.

This dataset provides rare measurements of CH₄ and CO₂ in the near-sea surface atmosphere above the Eastern Arctic Ocean and its marginal seas. These measurements are needed for Arctic carbon cycle studies and understanding emissions of CH₄ from marine sources in the Arctic.

Measurements were made onboard the Swedish icebreaker Oden during leg 1 of the SWERUS-C3 expedition to the Arctic Ocean.

Citation

Brett Thornton, Marc Geibel, Patrick Crill, Christoph Humborg (2016). Atmospheric methane and carbon dioxide and surface water methane from the SWERUS-C3 Arctic Ocean expedition in 2014, leg 1. Dataset version 1.0. Bolin Centre Database. https://doi.org/10.17043/thornton-2016

References

Thornton BF, Geibel MC, Crill PM, Humborg C, Mörth C‐M (2016). Methane fluxes from the sea to the atmosphere across the Siberian shelf seas. Geophys. Res. Lett. 43, 5869⁠ – 5877, https://doi.org/10.1002/2016GL068977

Data description

The data are included in three comma-separated values (csv) files:

1. SWERUS_leg1_air_GHG_temporal.csv

   • Calibrated CH₄, CO₂ in ppm, measured in the air at 4, 9, 15, 20, and 35 m heights above sea surface.
   • Standard deviation of CH₄ and CO₂, in ppm.
   • GPS (day of year, latitude, longitude).
   • valve position (inlet height, see below).

   Data are provided for day of year 192⁠ – 229. The atmospheric data have been filtered for windspeed, wind direction, and CO₂ > 450 ppm (filters are designed to remove possible ship influence from data).

   Valve position corresponds to measurement height above sea level: 1 = 4 m (rarely used), 2 = 9 m, 3 = 20 m, 4 = 15 m, 5 = 35 m.

2. SWERUS_leg1_water_GHG_temporal.csv

   • Calibrated dissolved CH₄ in ppm, data measured from an intake in the hull of Oden at ca. 8 m depth.
   • GPS (latitude, longitude, day of year).
   • seawater salinity.
   • seawater temperature.
   • seawater pH.
   • 10 m windspeed (corrected from measurement height).

   Data are provided for day of year 189⁠ – 222.

3. SWERUS_leg1_air_water_GHG_spatial.csv

   • Includes coincident air and water measurements from days 192⁠ – 222.

   Same measurements as above, but all measurements have been gridded and averaged to 0.001 degree resolution (a spatial normalization process which accounts for varying ship speed during the cruise).

Some further details are provided in a readme pdf file.

Comments

Atmospheric CH₄ and CO₂ data for leg 2 of SWERUS-C3 are also available.