Observation-Based Estimate of Net Community Production in Antarctic Sea Ice

Abstract

Antarctic sea ice is one of the largest biomes on Earth providing a critical habitat for ice algae. Measurements of primary production in Antarctic sea ice remain scarce and an observation‐based estimate of primary production has not been revisited in over 30 years. We fill this knowledge gap by presenting a newly compiled circumpolar data set of particulate and dissolved organic carbon from 362 ice cores, sampled between 1989 and 2019, to estimate sea‐ice net community production using a carbon biomass accumulation approach. Our estimate of 26.8–32.9 Tg C yr⁻¹ accounts for at least 15%–18% of the total primary production in the Antarctic sea‐ice zone, less than a previous observation‐based estimate (63–70 Tg C yr⁻¹ ) and consistent with recent modeled estimates. The results underpin the ecological significance of sea‐ice algae as an early season resource for pelagic food webs.