Nutrients in seawater, ice, brine, lead, slush, and under-ice water from expedition ARTofMELT, Arctic Ocean 2023

Samantha C. Rush, Penny Vlahos

This is the raw data for nutrients 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.

The objective of the study was to evaluate the carbonate system in sea ice with the onset of melt. This dataset includes the nutrient measurements and their error that support such analyses; phosphate, silicate, ammonia, and nitrate + nitrate.

The dataset also contains location, salinity, date, and water/ice/snow depth information across the sample types.

MarineWater qualityPhosphateSilicateAmmoniaNitrateNitriteNutrientsArcticArctic OceanARTofMELTARTofMELT 2023 expeditionIcebreaker Oden

Name

Version

Citation

References

American Public Health Association (1997) Standard Method 4500-NH3 Nitrogen (Ammonia) 108–117. Accessed March 5, 2025. https://www.nemi.gov/methods/method_summary/7410/

American Public Health Association (1999) Standard Method 4500-P Phosphorus (Phosphate) 146-162. Accessed March 5, 2025. https://www.nemi.gov/methods/method_summary/7436/

American Public Health Association (2011) Standard Method 4500-NO3- Nitrogen (Nitrate) 120–129. Accessed March 5, 2025. https://law.resource.org/pub/us/cfr/ibr/002/apha.method.4500-no3.1992.pdf

Environmental Protection Agency (1993) EPA Method 353.2, Revision 2.0: Determination of Nitrate-Nitrite Nitrogen by Automated Colorimetry 0–14. Accessed March 5, 2025. https://www.epa.gov/sites/default/files/2015-08/documents/method_353-2_1993.pdf

Environmental Protection Agency (1997) Methods for the Determination of Chemical Substances in Marine and Estuarine Environmental Samples. Method 366.0: Determination of Dissolved Silicate in Estuarine and Coastal Waters by Gas Segmented Continuous Flow Colorimetric Analysis. Accessed March 5, 2025. https://www.nemi.gov/methods/method_summary/4661/

Data description

The dataset is provided in one comma-separated values (csv) file with 172 rows and 22 columns with the following headers and content:

• station Station number
• core Core number
• cast Cast number
• water_column_depth_m Water column depth (m)
• ice_core_depth_cm Ice core depth (cm)
• date Date (dd-mm-yy)
• latitude Latitude (decimal degrees north)
• longitude Longitude (decimal degrees east)
• salinity Practical salinity (‰)
• sample_type Sample type (text)
• PO43 PO₄³⁻ concentration (μM)
• PO43_sd PO₄³⁻ standard deviation (μM)
• PO43_rds PO₄³⁻ relative standard deviation (%)
• NH3 NH₃ concentration (μM)
• NH3_sd NH₃ standard deviation (μM)
• NH3_rsd NH₃ relative standard deviation (%)
• Si Si concentration (μM)
• Si_sd Si standard deviation (μM)
• Si_rsd Si relative standard deviation (%)
• NOx NOx concentration (μM)
• NOx_sd NOx standard deviation (μM)
• NOx_rsd NOx relative standard deviation (%)

Comments

Subsets of water for nutrient analysis were collected by filtering through a pre-combusted, pre-weighed 25 mm glass fiber filter (GF/F, 0.7 µm nominal pore size, Whatman). Filtered water was collected into 20 mL plastic scintillation vials in duplicate for nutrient analysis, frozen to −80 °C. Following the expedition, samples were shipped to the US and stored at −20 °C.

Ammonia (NH₃), phosphate (PO₄³⁻), silicate (SiO₃²⁻), and NOx (nitrate (NO₃⁻) + nitrite (NO₂⁻)) were analyzed using a SmartChem 200 discrete auto-analyzer (Unity Scientific, Milford, MA) at the University of Connecticut at a lab temperature of 20 deg C.

For samples of high salinity (S > 13), nutrient analysis was conducted in an artificial seawater matrix of 30 ppt, and for lower salinity samples (S ≤ 13), nutrient analysis was conducted in a Milli-Q background.

Ammonia was measured following SM-4500-NH3F (APHA 1997) and calibrated against standard solutions ranging from 0 to 20 µM (LOD < 0.78µM). LOD is the limit of detection.

Phosphate was measured following SM 4500-P-E (APHA 1999) and calibrated against standard solutions ranging from 0 to 20 µM (LOD 0.35 µM).

Silicate was measured following SmartChem 200 Method SW-SiO2-1 for silicic acid (silica) in seawater modified from the EPA method (EPA 1997) and calibrated against standard solutions ranging from 0 to 100 µM (LOD < 0.86 µM).

NOx was measured following SM 4500-NO3-E (APHA 2011) and EPA 353.2, Rev. 2 (EPA 1993) by Cd reduction and calibrated against standard solutions ranging from 0 to 40 µM (LOD < 1.29 µM).

The reported nutrient concentration is either that of a sample duplicate with a relative standard deviation (RSD, %) of less than 20 or that of a single sample where the duplicate RSD ≥ 20%. The reported nutrient concentration is the lower duplicate nutrient concentration measured to be most conservative in cases of RSD ≥ 20%.

Blanks in the datasheet indicate that the no nutrient measurements were made for that particular sample. N.D. indicates non-detect, where the measured nutrient concentration was below the limit of detection.

Project

ARTofMELT 2023 expedition

Publisher

Bolin Centre Database

License

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

GCMD location

Ocean > Arctic Ocean

Dataset language

English

Begin date

2023-05-07

End date

2023-06-15

DOI

Time