Annual changes in oceanic and atmospheric carbon dioxide (CO₂) in the western North Pacific

Updated on 31 Jan. 2024
Japan Meteorological Agency

The growth rates for oceanic and atmospheric CO₂ partial pressure (pCO₂) are 1.5–2.8 and 1.8–2.1 µatm/year, respectively.

Annual changes in oceanic and atmospheric pCO₂ along the 137°E (left) and the 165°E (right) lines.
•Black plots show oceanic pCO₂ observation values(text data:137°E 165°E).
•Solid lines represent monthly oceanic pCO₂ values reconstructed using the method of Ishii et al. (2011)(text data:137°E 165°E), dashed lines show the long-term trend of oceanic pCO₂.
•Gray lines indicate the observed values of atmospheric pCO₂(text data:137°E 165°E).

Commentary

The growth rates for oceanic and atmospheric pCO₂ along the line 137°E from 1985 to 2023 were 1.5–2.1 and 1.8–2.0 µatm/year, respectively. Those along the line 165°E from 1996 to 2023 were 1.8–2.8 and 1.9–2.1 µatm/year, respectively. The increase in oceanic pCO₂ is associated with a monotonous increase in atmospheric pCO₂ caused by anthropogenic emissions, as the ocean absorbs around a third of all CO₂ emissions in the atmosphere.

Time-latitude distribution of oceanic pCO₂ along the 137°E (left) and the 165°E (right) lines.

Colors indicate reconstructed monthly oceanic pCO₂ value. The part on the left shows oceanic pCO₂ along the 137°E (3-34°N) since 1985 and the part on the right shows oceanic pCO₂ along the 165°E (5°S-35°N) since 1996.

Refecences

• Ishii, M., N. Kosugi, D. Sasano, S. Saito, T. Midorikawa, and H. Y. Inoue (2011), Ocean acidification off the south coast of Japan: A result from time series observations of CO₂ parameters from 1994 to 2008, J. Geophys. Res., 116, C06022, doi:10.1029/2010JC006831.