Feely¹, R.A., Y. Nojiri², C.L. Sabine¹, A. Dickson³ and M.F. Lamb¹

¹NOAA/PMEL, 7600 Sand Point Way NE, Seattle, WA, 98115 USA, Tel: 206-526-6214, Fax: 206-526-6744, E-mail: feely@pmel.noaa.gov, ²National Institute for Environmental Studies, Tsukuba, Ibaraki, 305-0053, Japan and ³Marine Physical Laboratory, Scripps Institution of Oceanography, La Jolla, CA 92093-0902 USA

PICES Working Group 13 on CO₂ in the North Pacific

The North Pacific Ocean is an important sink for atmospheric carbon dioxide. Some biogeochemical processes relating to the oceanic CO₂ system are enhanced there. This occurs because: (a) the North Pacific is the final destination for circulation of the deep water that contains high levels of dissolved inorganic carbon and preformed nutrients; and (b) the North Pacific Intermediate Water stores anthropogenic carbon dioxide for several decades. Surface waters are estimated to have total concentrations of anthropogenic CO₂ of up to 40-50 µmol kg^-1. Time-series measurements indicate the invasion of anthropogenic CO₂ to maximum depths of approximately 1250 m in the subtropics and shallower depths in the subarctic regions.

The PICES Working Group 13 on CO₂ in the North Pacific supported international scientific activities by (a) co-sponsoring several scientific symposia on the CO₂ system dynamics and CO₂ data synthesis in the North Pacific, (b) conducting two international laboratory inter-comparison exercises for DIC and Talk (15 laboratories from 6 countries were involved in this activity), and (c) developing a mechanism for international data exchange. The work is continuing through the efforts of the PICES Working Group 17 on Biogeochemical data integration and synthesis.