Evaluation of the net CO2 uptake in the Canada Basin in the summer of 2008

• Published in: Acta oceanologica Sinica 2017-08, Vol.36 (8), p.94-100
• Main Authors: Sun, Heng, Gao, Zhongyong, Lu, Peng, Xiu, Peng, Chen, Liqi
• Format: Article
• Language: English
• Subjects: Arctic research; Atmosphere; Balancing; Basins; Blooms; Carbon dioxide; Carbon dioxide atmospheric concentrations; Carbon dioxide flux; Carbon dioxide measurements; Carbon dioxide removal; Chemical analysis; Climatology; Dilution; Earth and Environmental Science; Earth Sciences; Ecology; Engineering Fluid Dynamics; Environmental Chemistry; Evaluation; Expeditions; Ice; Ice cover; Marine & Freshwater Sciences; Measurement; Oceanography; Partial pressure; pCO2; Removal; Research expeditions; Seawater; Summer; Surveying; Surveys; Temperature (air-sea); Uptake; Water analysis; Water sampling; 二氧化碳分压; 加拿大海盆; 吸收量; 夏季; 大气CO2; 表层海水; 评价
• ISSN: 0253-505X; 1869-1099
• DOI: 10.1007/s13131-017-1028-9

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 （pCO2） was measured, and sea water samples were collected for CO2 measurement in the Canada Basin. The distribution of pCO2 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°N）, the partially ice-covered zone （77°-80°N）, and the heavily ice-covered zone （north of 80°N）. In the ice-free zone, pCO2 was high （320 to 368 patm, 1 patm=0.101 325 Pa）, primarily due to rapid equilibration with atmospheric CO2 over a short time. In the partially ice-covered zone, the surface pCOs was relatively low （250 to 270 patm） due to ice-edge blooms and icemelt water dilution. In the heavily ice-covered zone, the seawater pCO2 varied between 270 and 300 laatm due to biological COs removal, the transportation of low pCOs water northward, and heavy ice cover. The surface seawater pCO2 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 CO2 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 COs 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 COs sink.