Direct Observations of Basin-wide Acidification of the North Pacific Ocean

Authors

Robert H. Byrne, University of South FloridaFollow
Sabine Mecking, University of Washington
Richard A. Feely, Pacific Marine Environmental Laboratory, NOAA, Seattle, Washington, USA
Xuewu Liu, University of South FloridaFollow

Document Type

Article

Publication Date

2010

Keywords

seawater pH, ocean acidification rates, pH variability

Digital Object Identifier (DOI)

https://doi.org/10.1029/2009GL040999

Abstract

Global ocean acidification is a prominent, inexorable change associated with rising levels of atmospheric CO₂. Here we present the first basin-wide direct observations of recently declining pH, along with estimates of anthropogenic and non-anthropogenic contributions to that signal. Along 152°W in the North Pacific Ocean (22–56°N), pH changes between 1991 and 2006 were essentially zero below about 800 m depth. However, in the upper 500 m, significant pH changes, as large as −0.06, were observed. Anthropogenic and non-anthropogenic contributions over the upper 800 m are estimated to be of similar magnitude. In the surface mixed layer (depths to ∼100 m), the extent of pH change is consistent with that expected under conditions of seawater/atmosphere equilibration, with an average rate of change of −0.0017/yr. Future mixed layer changes can be expected to closely mirror changes in atmospheric CO₂, with surface seawater pH continuing to fall as atmospheric CO₂ rises.

Rights Information

Terms of use for work posted in Scholar Commons.

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Geophysical Research Letters, v. 37, issue 2, art. L02601

Copyright 2010 by the American Geophysical Union.

Scholar Commons Citation

Byrne, Robert H.; Mecking, Sabine; Feely, Richard A.; and Liu, Xuewu, "Direct Observations of Basin-wide Acidification of the North Pacific Ocean" (2010). Marine Science Faculty Publications. 1590.
https://digitalcommons.usf.edu/msc_facpub/1590