The carbonate chemistry in the Dalton Polynya in East Antarctica (115°–123°E) was investigated in summer 2014/2015 using high‐frequency underway measurements of CO2fugacity (
We determined the impact of anthropogenic CO2(Cant) accumulation on the δ13C of dissolved inorganic carbon in the Arctic Ocean (i.e., the13C Suess effect) based on δ13C measurements during a GEOTRACES cruise in 2015. The δ13C decrease was estimated from the amount of Cantchange derived by the transit time distribution approach and the ratio of the anthropogenic δ13C/dissolved inorganic carbon change (RC). A significant Cantincrease (up to 45 μmol kg−1) and δ13C decrease (up to −0.9‰) extends to ~2,000 m in the Canada and Makarov Basin. We find distinctly different RC values for the intermediate water (300–2,000 m) and upper halocline water (<200 m) of −0.020 and −0.012‰ (μmol kg−1)−1, respectively, which identifies two sources of Cantaccumulation from North Atlantic and North Pacific. Furthermore, estimated RC for intermediate waters is the same as the RC observed in the Greenland Sea and the rate of anthropogenic dissolved inorganic carbon increase estimated for intermediate waters at 0.9 μmol kg−1yr−1is identical to the estimated rate in the Iceland Sea. These observations indicate that the high rate of Cantaccumulation and δ13C decrease in the Arctic Ocean is primarily a result of the input of Cant, via ventilation of intermediate waters, from the Nordic Sea rather than local anthropogenic CO2uptake within the Arctic Basin. We determine the preindustrial δ13C (δ13CPI) distributions and find distinct δ13CPIsignatures of the intermediate and upper halocline waters that reflect the difference in δ13CPI–PO4relationship of Atlantic and Pacific source water.
more » « less- NSF-PAR ID:
- 10455673
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Global Biogeochemical Cycles
- Volume:
- 34
- Issue:
- 2
- ISSN:
- 0886-6236
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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