Abstract
Abstract. At present, although seasonal sea-ice cover mitigates atmosphere-ocean gas exchange, the Arctic Ocean takes up carbon dioxide (CO2) on the order of −66 to −199 Tg C year−1 (1012 g C), contributing 5–14% to the global balance of CO2 sinks and sources. Because of this, the Arctic Ocean has an important influence on the global carbon cycle, with the marine carbon cycle and atmosphere-ocean CO2 exchanges sensitive to Arctic Ocean and global climate change feedbacks. In the near-term, further sea-ice loss and increases in phytoplankton growth rates are expected to increase the uptake of CO2 by Arctic Ocean surface waters, although mitigated somewhat by surface warming in the Arctic. Thus, the capacity of the Arctic Ocean to uptake CO2 is expected to alter in response to environmental changes driven largely by climate. These changes are likely to continue to modify the physics, biogeochemistry, and ecology of the Arctic Ocean in ways that are not yet fully understood. In surface waters, sea-ice melt, river runoff, cooling and uptake of CO2 through air-sea gas exchange combine to decrease the calcium carbonate (CaCO3) mineral saturation states (Ω) of seawater while seasonal phytoplankton primary production (PP) mitigates this effect. Biological amplification of ocean acidification effects in subsurface waters, due to the remineralization of organic matter, is likely to reduce the ability of many species to produce CaCO3 shells or tests with profound implications for Arctic marine ecosystems
Highlights
Introduction2002; Serreze and Francis, 2006; Overland et al, 2008), seaice loss (Cavalieri et al, 2003; Maslanik et al, 2007; Shimada et al, 2007; Giles et al, 2008; Comiso et al, 2008), and other physical changes (Wu et al, 2006; McGuire et al, 2006) as well as biology and ecosystem structure changes (Arrigo et al, 2008; Pabi et al, 2008)
Since brine rejection and formation of dense water appears to facilitate uptake of CO2 from the atmosphere (Anderson et al, 2004; Omar et al, 2005), enhanced opening of polynyas and leads may increase the sink of CO2 in the Arctic Ocean in the nearfuture depending on inorganic carbon distributions and future air-sea CO2 disequilibrium
Seasonal sea-ice cover provides a barrier to atmosphere-ocean gas exchange, the Arctic Ocean is a sink for CO2, on the order of −65 to −199 Tg C year−1, contributing 5–14% to the global balance of CO2 sinks and sources
Summary
2002; Serreze and Francis, 2006; Overland et al, 2008), seaice loss (Cavalieri et al, 2003; Maslanik et al, 2007; Shimada et al, 2007; Giles et al, 2008; Comiso et al, 2008), and other physical changes (Wu et al, 2006; McGuire et al, 2006) as well as biology and ecosystem structure changes (Arrigo et al, 2008; Pabi et al, 2008) These changes and feedbacks could have profound impacts on the Arctic Ocean marine carbon cycle and the importance of the Arctic for the global carbon cycle and the balance of carbon dioxide (CO2) sinks and sources. We review the present understanding of the marine inorganic carbon cycle, air-sea CO2 disequilibrium and rates of air-sea CO2 gas exchange, the physical and biological processes that influence Arctic Ocean CO2 sinks and sources, the impact of ocean acidification and the potential future drivers of change such as sea-ice loss, phytoplankton primary production (PP) and freshwater inputs. We discuss the impact of ocean acidification, and biological and physical processes on the marine carbon cycle and calcium carbonate (CaCO3) mineral saturation states in the Arctic Ocean (Sect. 6)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
