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Indexed by:期刊论文

Date of Publication:2017-08-01

Journal:ACTA OCEANOLOGICA SINICA

Included Journals:SCIE、Scopus

Volume:36

Issue:8

Page Number:94-100

ISSN No.:0253-505X

Key Words:Canada Basin; net CO2 uptake; partial pressure of CO2

Abstract:The third Chinese National Arctic Research Expedition (CHINARE) was conducted in the summer of 2008. During the survey, the surface seawater partial pressure of CO2 (pCO(2)) was measured, and sea water samples were collected for CO2 measurement in the Canada Basin. The distribution of pCO(2) in the Canada Basin was determined, the influencing factors were addressed, and the air-sea CO2 flux in the Canada Basin was evaluated. The Canada Basin was divided into three regions: the ice-free zone (south of 77 degrees N), the partially ice-covered zone (77 degrees-80 degrees N), and the heavily ice-covered zone (north of 80 degrees N). In the ice-free zone, pCO(2) was high (320 to 368 mu atm, 1 mu atm=0.101 325 Pa), primarily due to rapid equilibration with atmospheric CO, over a short time. In the partially ice-covered zone, the surface pCO(2) was relatively low (250 to 270 mu atm) due to ice-edge blooms and ice melt water dilution. In the heavily ice-covered zone, the seawater pCO(2) varied between 270 and 300 mu atm due to biological CO2 removal, the transportation of low pCO(2) water northward, and heavy ice cover. The surface seawater pCO(2) during the survey was undersaturated with respect to the atmosphere in the Canada Basin, and it was a net sink for atmospheric CO2. The summertime net CO, uptake of the ice-free zone, the partially ice-covered zone and the heavily ice-covered zone was (4.14 +/- 1.08), (1.79 +/- 0.19), and (0.57 +/- 0.03) Tg/a (calculated by carbon, 1 Tg=10(12) g), respectively. Overall, the net CO2 sink of the Canada Basin in the summer of 2008 was (6.5 +/- 1.3) Tg/a, which accounted for 4%-10% of the Arctic Ocean CO2 sink.