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Polar oceans are chemically sensitive to anthropogenic acidification due to their relatively low alkalinity and correspondingly weak carbonate buffering capacity. Here, we compare unique CO2 system observations covering complete annual cycles at an Arctic (Amundsen Gulf) and Antarctic site (Prydz Bay). The Arctic site experiences greater seasonal warming (10 vs 3°C), and freshening (3 vs 2), has lower alkalinity (2220 vs 2320 μmol/kg), and lower summer pH (8.15 vs 8.5), than the Antarctic site. Despite a larger uptake of inorganic carbon by summer photosynthesis, the Arctic carbon system exhibits smaller seasonal changes than the more alkaline Antarctic system. In addition, the excess surface nutrients in the Antarctic may allow mitigation of acidification, via CO2 removal by enhanced summer production driven by iron inputs from glacial and sea-ice melting. These differences suggest that the Arctic system is more vulnerable to anthropogenic change due to lower alkalinity, enhanced warming, and nutrient limitation.

Item Type:	Refereed Article
Keywords:	Cryospheric science, Biogeochemistry, Ocean sciences, Marine chemistry
Research Division:	Earth Sciences
Research Group:	Oceanography
Research Field:	Chemical oceanography
Objective Division:	Environmental Policy, Climate Change and Natural Hazards
Objective Group:	Understanding climate change
Objective Field:	Effects of climate change on Antarctic and sub-Antarctic environments (excl. social impacts)
UTAS Author:	Shadwick, EH (Dr Elizabeth Shadwick)
UTAS Author:	Trull, T (Professor Thomas Trull)
UTAS Author:	Gibson, JAE (Dr John Gibson)
ID Code:	85756
Year Published:	2013
Web of Science® Times Cited:	58
Deposited By:	CRC-Antarctic Climate & Ecosystems
Deposited On:	2013-08-06
Last Modified:	2014-05-09
Downloads:	753 View Download Statistics