Re-Estimation of Annual Anthropogenic Carbon Input from Oyashio into North Pacific Intermediate Water

摘要

The annual transport of anthropogenic carbon (Canth) to the North Pacific Intermediate Water (NPIW) from the Western Subarctic Gyre (WSG) has been re-estimated by using newly estimated Oyashio transport and Canth concentration, the latter calculated by the recently-established “ΔC*” method with some modifications. Estimated annual Canth transport through the nearshore Oyashio west of 146°E was 0.020 ± 0.010 GtC y?1, closely approximating the previous estimation based on a 1-D model calibrated with the CFC vertical distribution. The present study, however, found that an additional 0.025 ± 0.010 GtC y?1 of Canth was transported into NPIW in the region east of 146°E. Total Canth transport, 0.045 GtC y?1, contributes about 35% of annual Canth accumulation of the whole temperate North Pacific.