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Decadal Changes in the Aragonite and Calcite Saturation State of the Pacific Ocean
Global Biogeochemical Cycles
  • Richard A. Feely, Corresponding Author
  • Christopher L. Sabine, Pacific Marine Environmental Laboratory, NOAA, Seattle, Washington, USA
  • Robert H. Byrne, University of South Florida
  • Frank J. Millero, University of Miami
  • Andrew G. Dickson, University of California
  • Rik Wanninkhof, Atlantic Oceanographic and Meteorological Laboratory, NOAA, Miami, Florida, USA
  • Akihiko Murata, Research Institute for Global Change
  • Lisa A. Miller, Institute of Ocean Sciences
  • Dana Greeley, Pacific Marine Environmental Laboratory, NOAA, Seattle, Washington, USA
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Publication Date
  • Pacific Ocean,
  • acidification,
  • aragonite,
  • calcite,
  • carbon dioxide,
  • saturation state
Digital Object Identifier (DOI)

Based on measurements from the WOCE/JGOFS global CO2 survey, the CLIVAR/CO2 Repeat Hydrography Program and the Canadian Line P survey, we have observed an average decrease of 0.34% yr−1 in the saturation state of surface seawater in the Pacific Ocean with respect to aragonite and calcite. The upward migrations of the aragonite and calcite saturation horizons, averaging about 1 to 2 m yr−1, are the direct result of the uptake of anthropogenic CO2 by the oceans and regional changes in circulation and biogeochemical processes. The shoaling of the saturation horizon is regionally variable, with more rapid shoaling in the South Pacific where there is a larger uptake of anthropogenic CO2. In some locations, particularly in the North Pacific Subtropical Gyre and in the California Current, the decadal changes in circulation can be the dominant factor in controlling the migration of the saturation horizon. If CO2 emissions continue as projected over the rest of this century, the resulting changes in the marine carbonate system would mean that many coral reef systems in the Pacific would no longer be able to sustain a sufficiently high rate of calcification to maintain the viability of these ecosystems as a whole, and these changes perhaps could seriously impact the thousands of marine species that depend on them for survival.

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Global Biogeochemical Cycles, v. 26, issue 3, art. GB3001

©2012. American Geophysical Union. All Rights Reserved.

Citation Information
Richard A. Feely, Christopher L. Sabine, Robert H. Byrne, Frank J. Millero, et al.. "Decadal Changes in the Aragonite and Calcite Saturation State of the Pacific Ocean" Global Biogeochemical Cycles Vol. 26 Iss. 3 (2012)
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