Temporal changes in dissolved oxygen of the intermediate water in the subarctic North Pacific

Abstract

[1] Using an approximately 50-year data set, the changes in dissolved oxygen (DO) ). It is hypothesized that the changes are correlated with the North Pacific Index (NPI), which fosters meridional transport of salt to the Bering Sea when it is high. The gradual decrease in NPI thus has caused a freshening and a subsequent decrease in the ventilation resulting in an AOU increase in the intermediate waters of the subarctic North Pacific.

Reconstruction of sea surface dimethylsulfide in the North Pacific during 1970s to 2000s

“…The weakening of the surface-deep water mixing was caused by both the increasing temperature and the decreasing salinity in the two regions Andreev and Watanabe, 2002;Watanabe et al, 2003;Watanabe et al, 2005). Consequently, MLD has shoaled although the long-term trend of MLD has been not significant due to large variation, and the nutrients in the surface mixed layer have decreased (Watanabe et al, 2005).…”

Simulation of anthropogenic CO<sub>2</sub> uptake in the CCSM3.1 ocean circulation-biogeochemical model: comparison with data-based estimates

“…The heat content of the world ocean has increased substantially over the past few decades (Levitus et al, 2000(Levitus et al, , 2005 along with the global averaged sea surface temperature (Hansen et al, 2006(Hansen et al, , 2010. Dissolved oxygen concentrations have also decreased in several ocean basins (Stramma et al, 2009;Matear et al, 2000;Andreev and Watanabe, 2002;Keller et al, 2002). These changes can affect the air-sea S. Wang et al: Simulation of anthropogenic CO 2 uptake in the CCSM3.1 1323 CO 2 flux and the carbon pumps, and therefore impact carbon storage in the ocean.…”

“…Hall et al, 2002;Waugh et al, 2006;Khatiwala et al, 2009) to estimate the anthropogenic carbon uptake. Since the estimates by Brewer (1978) and Chen and Millero (1979), several alternative back-calculation methods have been developed to estimate anthropogenic CO 2 concentrations in the ocean. Of these, one of the most widely used is the C* method developed by Gruber et al (1996).…”

Seasonal and Interannual Variation of DIC in Surface Mixed Layer in the Oyashio Region: A Climatological View

“…Long-period variation has also been stated to occur in its subsurface in relation to the long-term water circulation change (e.g., Ono et al, 2001;Watanabe et al, 2001;Andreev and Watanabe, 2002;Emerson et al, 2004). A distinct amount of anthropogenic carbon is pumped down from the mixed layer of this region into the North Pacific Intermediate Water (Tsunogai et al, 1993;Ono et al, 2000aOno et al, , 2003, the formation rate of which, and hence the annual flux of anthropogenic carbon, is also expected to be changed by long-term water circulation change Ono et al, 2002Ono et al, , 2003.…”