The Ocean Carbon Cycle in the Western Arctic Ocean: Distributions and Air-Sea Fluxes of Carbon Dioxide

Nicholas Bates,Wei-Jun Cai,Jeremy Mathis

doi:10.5670/oceanog.2011.71

Abstract

The Arctic Ocean is a potentially important sink for atmospheric carbon dioxide (CO2) with a recent estimate suggesting that the region contributes from 5 to 14% of the global ocean's net uptake of CO2. In the western Arctic Ocean, the focus of this paper, the Chukchi Sea is a strong ocean sink for CO2 that is partially compensated for by outgassing of CO2 from the East Siberian Sea shelf. The Arctic marine carbon cycle and exchange of CO2 between the ocean and atmosphere appear particularly sensitive to environmental changes, including sea ice loss, warming, changes in seasonal marine phytoplankton primary production, changes in ocean circulation and freshwater inputs, and even the impacts of ocean acidification. In the near term, further sea ice loss, increases in phytoplankton growth rates, and other environmental and physical changes in the Arctic are expected to cause a limited net increase in the uptake of CO2 by Arctic surface waters. Recent studies suggest that this enhanced uptake will be short lived, with surface waters rapidly warming and equilibrating with the atmosphere. Furthermore, release of large stores of carbon from the surrounding Arctic landmasses through rivers into the Arctic Ocean and further warming over the next century may alter the Arctic from a CO2 sink to a source over the next century.

Highlights

The Arctic Ocean is sensitive to atmosphereocean-sea ice forcing and feedbacks and ecosystem transitions associated with warming temperatures and sea ice loss (e.g., Arrigo et al, 2008; Pabi et al, 2008)
The Arctic marine carbon cycle and marine ecosystems are vulnerable to ocean acidification that results from the uptake of anthropogenic CO2 from the atmosphere (Orr et al, 2005; Steinacher et al, 2009; Bates et al, 2009; Yamamoto-Kawai et al, 2009)
We review the present state of knowledge about the Arctic marine carbon cycle, exchanges of CO2 between the atmosphere and the ocean, and the potential physical and biological processes that influence CO2 sources and sinks in the PacificOcean-influenced Arctic

Summary

The Ocean Carbon Cycle in the Western Arctic Ocean

The Arctic Ocean is sensitive to atmosphereocean-sea ice forcing and feedbacks and ecosystem transitions associated with warming temperatures and sea ice loss (e.g., Arrigo et al, 2008; Pabi et al, 2008) Because of these rapid environmental changes, the Arctic marine carbon cycle will likely enter a highly dynamic state in the coming decades, with large uncertainties in the exchange of atmosphere-ocean CO2 (Anderson and Kaltin, 2001; Bates et al, 2006a; Bates and Mathis, 2009; Cai et al, 2010; Jutterström and Anderson, 2010) in response to sea ice loss and other climate-change-induced processes. The expansive coastal seas of the Arctic Ocean (e.g., Barents, Laptev, Kara, East Siberian, Chukchi, and Beaufort Seas) comprise approximately 53% of its total area (Macdonald et al, 2010)

Kara Sea

Beaufort Sea Central Basin

Findings

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