Temporal increases of phosphate and apparent oxygen utilization in the subsurface waters of western subarctic Pacific from 1968 to 1998

Decadal changes in the CaCO3 saturation state along 179°E in the Pacific Ocean

“…Same as Figure 1, but for DW arg above 1000 dbar due to the anthropogenic CO 2 contribution alone. particular, Byrne et al [2010] found accelerated acidification south of 50 N between 200 and 400 m depth and also at depths shallower than 250 m between 22 N and 32 N. Their result thus suggests that acceleration (and deceleration) of ocean acidification due to decadal AOU (and nC T org ) variability [Ono et al, 2001;Whitney et al, 2007] is widespread in the subtropical gyre of the North Pacific.…”

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

“…The anthropogenic increase of DIC corresponding to the increase of atmospheric carbon dioxide concentration is expected to be less than 0.5 µmol/kg/y in this region (e.g., Ono et al, 2000b), and thus the 8-year increase of DIC due to the anthropogenic effect is well below the detection limit of our database. Ono et al (2001) discovered the existence of a bidecadal oscillation in the subsurface concentration of apparent oxygen utilization, which suggests that DIC also shows natural long-term oscillations. This again does not conflict with the low interannual DIC variation observed in the present study, however, because the period from 1996 to 2003 is a peak phase of the AOU bidecadal oscillation where interannual variation is the smallest .…”

“…Although we have a twoyear time series data from station KNOT in the center of WSNP (Nojiri, 1998;Tsurushima et al, 2002;Imai et al, 2002), the Oyashio region has over 30 years of time series data for several hydrographic/geochemical parameters (e.g., Ono et al, 2001Ono et al, , 2002Chiba et al, 2004;Tadokoro et al, 2005). Furthermore, several institutes have measured DIC in this region from 1996 to the present, the aggregate of which gives an eight-year time series.…”

“…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.…”

Long-Term Changes of Greenhouse Gases in the Ocean and Their Feedback Effects on the Climate

“…In the North Pacific, some studies have already shown the changes of chemical components with the decrease of sea surface water density, suggesting a weakening of the surface-deep water mixing derived from artificial greenhouse warming effects and/or natural climate change (Ono et al 2001;Watanabe et al 2001Watanabe et al , 2003Emerson et al 2004). Consequently, the abundances of phytoplankton and Chl in the surface mixed layer have been shown to decrease in the North Pacific subpolar and subtropical regions (e.g., Gregg and Conkright 2002;Chiba et al 2004;Watanabe et al 2005).…”