Dissolved organic carbon and organic alkalinity in sea ice brine from expedition ARTofMELT, Arctic Ocean, 2023

Samantha C. Rush

This is the raw data for dissolved organic carbon and organic alkalinity in sea ice brine collected onboard the Swedish icebreaker Oden during the expedition ARTofMELT (Atmospheric Rivers and the Onset of Arctic Melt) in the Fram Strait pack ice during the spring transition, 8 May to 14 June of 2023.

This data set is from the chemical oceanography group aimed at understanding the inorganic carbon system within sea ice and the underlying water throughout the onset of a melt season. This data includes the dissolved organic carbon concentrations, organic alkalinity contribution (both directly measured via back-titrations and calculated via CO2SYS with pH and dissolved inorganic carbon data), and calculated carbonate parameters (pCO₂, pH, and CaCO₃ saturation states) depending on the inclusion or omission of the organic alkalinity component.

While total alkalinity is traditionally attributed to dissolved inorganic constituents, dissolved organic matter (DOM) can significantly contribute to total alkalinity, introducing errors in carbonate parameter calculations such as calcium carbonate (CaCO₃) saturation state (Ω) and partial pressure of carbon dioxide (pCO₂). Accurately quantifying organic alkalinity (OrgAlk) is particularly crucial in the rapidly changing Arctic. The data presented here is aimed at discerning the presence of OrgAlk in the Arctic Ocean and assesses its influence on carbonate speciation.

MarineMarine chemistryArcticArctic OceanOcean chemistryFram StraitAlkalinityOrganic carbonOrganic alkalinitypHBoronpCO₂Air-sea gas fluxARTofMELTARTofMELT 2023 expeditionIcebreaker Oden

Name

Version

Citation

References

Rush S, Lee C-H, Lee K, Yoon S-H, Vlahos P (2026) Neglecting organic alkalinity introduces greater error than assuming boron to salinity ratios in Arctic sea ice brine carbonate system calculations. Scientific Reports 16. https://doi.org/10.1038/s41598-026-39719-6

Rush, SC (2025) Dissolved Organic Carbon in the Arctic Ocean and Organic Alkalinity in Sea Ice Brine from ARTofMELT 2023. Arctic Data Center. https://doi.org/10.18739/A2KS6J65C

Data description

The dataset is provided in one comma-separated values (csv) file with 142 rows and 35 columns with the following headers:

• Sample Type
• Station
• Core
• Cast
• Water Column Depth (m)
• Ice Core Depth (cm)
• Snow Depth (cm)
• Latitude
• Longitude
• Salinity
• In-situ T (°C)
• Estimated In Situ T (°C)
• Organic Alkalinitymeas (µmol kg-1)
• Total X1 (μmol/kg)
• pK1
• Total X2 (μmol/kg)
• pK2
• Dissolved Organic Carbon (µM)
• OrgAlk/[DOC] (µmol kg-1 µM-1)
• OrgAlkmeas AT Contribution (%)
• AT,meas (µmol kg-1)
• AT,meas error (µmol kg-1)
• CT,meas (µmol kg-1)
• CT,meas error (µmol kg-1)
• pH25, meas
• pH25, meas error
• PO43- (µM)
• PO43- Standard Deviation(µM)
• PO43- Relative Standard Deviation (%)
• NH3 (µM)
• NH3 Standard Deviation (µM)
• NH3 Relative Standard Deviation (%)
• SiO2 (µM)
• SiO2 Standard Deviation (µM)
• SiO2 Relative Standard Deviation (%)

For a detailed description of dataset content, methods and sampling procedures, see text by Rush (2025) at the dataset site at the NSF Arctic Data Center.

Comments

Dataset publisher

The dataset is published by the NSF Arctic Data Center under the Creative Commons Universal 1.0 Public Domain Dedication.

Related article

The dataset was used to support the article by Rush et al. (2026) , which describes measured organic alkalinity in various sample types in the eastern Arctic Ocean and the uncertainty implications on subsequently calculated marine carbonate parameters.

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.

Project

ARTofMELT 2023 expedition. This dataset was collected within the project Discerning Boron to Salinity Ratios in Arctic Marginal Ice Zones - BAMZ, funded by the National Science Foundation. Grant number 2227313.

Publisher

NSF Arctic Data Center

License

CC0 1.0 Universal (CC0 1.0) Public Domain Dedication

First name

Samantha

Last name or organisation

Rush

Email address

samantha.rush@uconn.edu

Address

Department of Marine Sciences; University of Connecticut Avery Point

Postal code

06340

City

Groton

Province or state

Connecticut

Country

USA

GCMD science keyword

Earth science > Oceans > Ocean chemistry > Alkalinity

GCMD location

Ocean > Arctic Ocean

Dataset language

English

Begin date

2023-05-07

End date

2023-06-15

Time

Versions

• 1 2026-04-09T05:49:46.708+00:00
• 1 2026-04-08T21:30:56.331+00:00