Water vapor isotopic (δ¹⁸O, δ²H) observations from expedition ARTofMELT, Arctic Ocean, 2023

Ben Kopec, Valtteri Hyöky, Eric Klein, Jeffrey Welker

This dataset contains 5-minute resolution processed water vapor isotopic (δ¹⁸O, δD, deuterium excess) measurements made during the expedition ARTofMELT 2023 with Swedish icebreaker Oden in the Fram Strait pack ice during the spring transition, 12 May to 14 June, 2023.

The water vapor measurements were collected from the foredeck mast (at ~20 m above sea level).

These water isotopic observations trace ice-ocean-atmosphere interactions across a range of sea ice conditions, including the identification and quantification of evaporative fluxes and atmospheric moisture transport.

Map

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Leaflet | Map data from Gebco

Citation

Ben Kopec, Valtteri Hyöky, Eric Klein, Jeffrey Welker (2025) Water vapor isotopic (δ¹⁸O, δ²H) observations from expedition ARTofMELT, Arctic Ocean, 2023. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/oden-artofmelt-2023-water-vapor-isotopes-1

References

Akers PD, Kopec BG, Mattingly KS, Klein ES, Causey D, Welker JM (2020) Baffin Bay sea ice extent and synoptic moisture transport drive water vapor isotope (δ18O, δ2H, and deuterium excess) variability in coastal northwest Greenland. Atmospheric Chemistry and Physics 20:13929–13955. https://doi.org/10.5194/acp-20-13929-2020

Kopec B, Werner M, Mattingly K, Klein E, Akers P, Bailey H, Bonne J-L, Brunello C, Mustonen K-R, Welker J (2022) Arctic Water Isotope Network observations, vapor transport, and storm track site connections for September-November 2019. Arctic Data Center. https://doi.org/10.18739/A2JS9H884

Kopec B, Klein E, Akers P, Hyöky V, Mustonen K-R, Welker J (2023) Arctic Water Isotope Network (AWIN) long-term water vapor observations, 2017-2022. Arctic Data Center. https://doi.org/10.18739/A2XW47X8W

Kopec BG, Hyöky V, Klein E, Welker J (2025) Seawater isotopic (δ¹⁸O, δ²H) observations from expedition ARTofMELT, Arctic Ocean, 2023. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/oden-artofmelt-2023-seawater-isotopes-1

Steen-Larsen HC, Johnsen SJ, Masson-Delmotte V, Stenni B, Risi C, Sodemann H, Balslev-Clausen D, Blunier T, Dahl-Jensen D, Ellehøj MD, Falourd S, Grindsted A, Gkinis V, Jouzel J, Popp T, Sheldon S, Simonsen SB, Sjolte J, Steffensen JP, Sperlich P, Sveinbjörnsdóttir AE, Vinther BM, White JWC (2013) Continuous monitoring of summer surface water vapor isotopic composition above the Greenland Ice Sheet. Atmospheric Chemistry and Physics 13:4815–4828. https://doi.org/10.5194/acp-13-4815-2013

Data description

The data is provided in one comma-separated values (.csv) file with the following columns:

• datetime date and time
• H2O_ppmv water vapor concentration (ppmv)
• d18O_vapor δ¹⁸O (‰)
• dD_vapor δD (‰)
• dex_vapor deuterium excess (‰)

The temporal resolution is 5 minutes. Missing data are represented by empty cells.

Comments

Measurement system

Icebreaker Oden was equipped with a Picarro L2140-i water vapor isotope analyzer, which sampled water vapor continuously from ~20 m above the sea surface from the bow of the ship. This instrument continuously measures the water vapor concentration (ppmv) and oxygen and hydrogen isotope ratios (δ¹⁸O and δD, respectively) at ~1 hz resolution. Deuterium excess (d-excess; d) values were computed in the form of d=δD-8·δ¹⁸O. After calibration (described below), all data is aggregated to 5-minute averages.

Quality control

Quality control analysis is conducted for each instrument to exclude periods of obvious instrument issues, particularly if liquid water entered the collection lines. Beyond the standard instrument error checks (e.g., cavity temperature) documented in prior studies using similar instruments (Akers et al. 2020, Kopec et al. 2022), for shorter-term periods of missing data, the most common issue was clear evidence of liquid water that was present in the inlet lines, where obvious evaporation signals were observed in the data — marked by rapid increases in H₂O concentration, δ¹⁸O, and δD, and decrease in d-excess. These periods were excluded from the dataset. The resulting set of raw data from each site is then processed based on the protocols described below.

Calibration

To ensure quality comparable measurements to other AWIN sites (Kopec et al. 2023), we take the following steps in processing and calibrating the data:

1. Standard waters calibration. Regular measurement (typically every ~24 hours) of known standard waters was conducted to correct any instrument offset. The heavy isotopic standard used was USGS 45 (δ¹⁸O=-2.238‰, δD=-10.3‰) and the light isotopic standard used was USGS 49 (δ¹⁸O=-50.55‰, δD=-394.7‰).
2. Drift assessment and correction. Using standard waters, we assess any drift over time, and correct as necessary.
3. Humidity response correction. It is well known that these water vapor isotope analyzers can have a humidity bias where isotopic measurements made at low water vapor concentrations may yield different isotopic values than if measured at high vapor concentrations (Steen-Larsen et al. 2013). Following the protocol described by Akers et al. (2020), standard waters were measured under a range water vapor concentrations (regulated by dry air gas) to develop a correction curve to be applied to the ambient air data.

The ambient air raw data is processed with the above corrections applied to the dataset. With the calibrations completed, all data is on the VSMOW-SLAP scale. Deuterium excess values were computed from the calibrated data and all isotopic measurements were compiled into 5-minute averages and linked with the average location (latitude, longitude) during the measurement window.

Associated datasets

This dataset is directly complementary to the continuous seawater isotopic observations during ARTofMELT produced by Kopec et al. (2025).

The dataset is also complementary to other water vapor isotopic observations in the Arctic Water Isotope Network (AWIN; Kopec et al. 2023).

The expedition

Data were collected during the ARTofMELT 2023 expedition on board the Swedish icebreaker Oden, which was organized by the Swedish Polar Research Secretariat from 8 May through 14 June, 2023.