(Table 1) Nutrient concentrations and carbon isotopes of sea ice segments and brine sampled during Nathaniel B. Palmer cruises NBP98-07 and NBP06-08, Ross Sea


We examined controls on the carbon isotopic composition of sea ice brines and organic matter during cruises to the Ross Sea, Antarctica in November/December 1998 and November/December 2006. Brine samples were analyzed for salinity, nutrients, total dissolved inorganic carbon (sum CO2), and the 13C/12C ratio of Sum CO2 (d13C(sum CO2)). Particulate organic matter from sea ice cores was analyzed for percent particulate organic carbon (POC), percent total particulate nitrogen (TPN), and stable carbon isotopic composition (d13C(POC)). Sum CO2 in sea ice brines ranged from 1368 to 7149 µmol/kg, equivalent to 1483 to 2519 µmol/kg when normalized to 34.5 psu salinity (s sum CO2), the average salinity of Ross Sea surface waters. Sea ice primary producers removed up to 34% of the available sum CO2, an amount much higher than the maximum removal observed in sea ice free water. Carbonate precipitation and CO2 degassing may reduce s sum CO2 by a similar amount (e.g., 30%) in the most hypersaline sea ice environments, although brine volumes are low in very cold ice that supports these brines. Brine d13C(sum CO2) ranged from -2.6 to +8.0 per mil while d13C(POC) ranged from -30.5 to -9.2 per mil. Isotopic enrichment of the sum CO2 pool via net community production accounts for some but not all carbon isotopic enrichment of sea ice POC. Comparisons of s sum CO2, d13C(sum CO2), and d13C(POC) within sea ice suggest that epsilon p (the net photosynthetic fractionation factor) for sea ice algae is ~8 per mil smaller than the epsilon p observed for phytoplankton in open water regions of the Ross Sea. These results have implications for modeling of carbon uptake and transformation in the ice-covered ocean and for reconstruction of past sea ice extent based on stable isotopic composition of organic matter in sediment cores.

Values given as 'raw' values and normalized to 34.5 psu salinity. Depth-integrated POC represents the mean of all cores at each station. Data extracted in the frame of a joint ICSTI/PANGAEA IPY effort, see http://doi.pangaea.de/10.1594/PANGAEA.150150

Supplement to: Munro, David R; Dunbar, Robert B; Mucciarone, David A; Arrigo, Kevin R; Long, Matthew C (2010): Stable isotope composition of dissolved inorganic carbon and particulate organic carbon in sea ice from the Ross Sea, Antarctica. Journal of Geophysical Research, 115(C9), C09005

DOI https://doi.org/10.1594/PANGAEA.817328
Related Identifier IsSupplementTo https://doi.org/10.1029/2009JC005661
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.817328
Creator Munro, David R; Dunbar, Robert B ORCID logo; Mucciarone, David A ORCID logo; Arrigo, Kevin R (ORCID: 0000-0002-7364-876X); Long, Matthew C ORCID logo
Publisher PANGAEA
Publication Year 2010
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 404 data points
Discipline Earth System Research
Spatial Coverage (-175.000W, -78.000S, 166.000E, -64.000N); Ross Sea
Temporal Coverage Begin 1998-11-06T00:00:00Z
Temporal Coverage End 2006-11-09T00:00:00Z