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Abstract The North Water Polynya (NOW) is one of the most productive biological regions in the Arctic with high importance to Inuit and Greenlandic communities. To provide insights into the potential changes of this region as global temperatures rise, we investigated the sea ice and physical and biological oceanic responses of the NOW to low (2°C) and high (>3.5°C) levels of warming using the Community Earth System Model, version 1. As global temperatures increase, sea ice production decreases, spring open water area increases, and summer open water areas in the NOW region connect with open water in central Baffin Bay earlier in the melt season. These sea ice changes contribute to increased stratification, which in turn leads to increased concentrations of nutrient-rich West Greenland Irminger Waters at depth while decreasing surface nutrient concentrations. At low warming levels in the eastern NOW region, warmer water temperatures increase phytoplankton growth rates despite the decrease in surface nutrients, leading to an increase in peak primary production relative to the historical period. In contrast, for high warming in both the eastern and western NOW regions, biological primary production decreases, despite the warmer water temperatures, because increased stratification and decreased surface nutrient concentrations limit phytoplankton production. For all assessed warming levels, changing phytoplankton community composition drives a loss of ecosystem productivity at higher trophic levels. Internal variability plays a negligible role in driving these future sea ice and ocean changes, highlighting the importance of limiting further global temperature increases to avoid large changes to the NOW ecosystem. Significance StatementThe North Water Polynya (NOW) is one of the most productive biological regions in the Arctic with high importance to Inuit and Greenlandic communities. In this paper, we explore how sea ice and physical and biological ocean conditions will change under low (2°C) and high (>3.5°C) levels of global warming.
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This content will become publicly available on November 6, 2026
Cosmic dust reveals dynamic shifts in central Arctic sea-ice coverage over the past 30,000 years
Arctic sea-ice loss affects biological productivity, sustenance in coastal communities, and geopolitics. Forecasting these impacts requires mechanistic understanding of how Arctic sea ice responds to climate change, but this is limited by scarce long-term records. We present continuous 30,000-year reconstructions of sea-ice coverage from the Arctic Ocean based on measurements of two isotopes, thorium-230 and extraterrestrial helium-3, whose burial ratio changes with sea-ice coverage. We found that the central Arctic was perennially covered by sea ice during the last glaciation. Sea-ice cover retreated during the deglaciation approximately 15,000 years ago, culminating in seasonal sea-ice coverage in the warm early Holocene, before ice coverage increased into the late Holocene. Sea-ice changes closely correlate with biological nutrient consumption, supporting projections of a nutrient-starved central Arctic Ocean with continued sea-ice loss.
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- PAR ID:
- 10691442
- Publisher / Repository:
- American Association for the Advancement of Science
- Date Published:
- Journal Name:
- Science
- Volume:
- 390
- Issue:
- 6773
- ISSN:
- 0036-8075
- Page Range / eLocation ID:
- 628 to 632
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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