Abstract
Observations of changes in the properties of ocean waters have been restricted to surface1 or intermediate-depth waters2,3, because the detection of change in bottom water is extremely difficult owing to the small magnitude of the expected signals. Nevertheless, temporal changes in the properties of such deep waters across an ocean basin are of particular interest, as they can be used to constrain the transport of water at the bottom of the ocean and to detect changes in the global thermohaline circulation. Here we present a comparison of a trans-Pacific survey completed in 1985 (refs 4, 5) and its repetition in 1999 (ref. 6). We find that the deepest waters of the North Pacific Ocean have warmed significantly across the entire width of the ocean basin. Our observations imply that changes in water properties are now detectable in water masses that have long been insulated from heat exchange with the atmosphere.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Levitus, S., Antonov, J. I., Boyer, T. P. & Stephens, C. Warming of the world ocean. Science 287, 2225–2229 (2000)
Wong, A. P., Bindoff, N. L. & Church, J. A. Large–scale freshening of intermediate waters in the Pacific and Indian Oceans. Nature 400, 440–443 (1999)
Roemmich, D. & Wunsch, C. Apparent changes in the climatic state of the deep North Atlantic Ocean. Nature 307, 447–450 (1984)
Talley, L. D., Martin, M., Salameh, P. & the Oceanographic Data Facility. Transpacific Section in the Subpolar Gyre (TPS47): Physical, Chemical, and CTD Data, R/V Thomas Thompson TT190, 4 August 1985–7 September 1985 1–246 (Ref. 88–9, Scripps Inst. Of Oceanography, La Jolla, CA, 1988)
Talley, L. D., Joyce, T. & deSzoeke, R. A. Trans-Pacific sections at 47°N and 152°W: distribution of properties. Deep-Sea Res. (Suppl.) 38, S63–S82 (1991)
Uchida, H., Fukasawa, M. & Freeland, H. J. WHP P01 Revisit Data Book 1–73 (Jamstec, Yokosuka, 2002)
Johnson, G. C., Rudnick, D. L. & Taft, B. A. Bottom water variability in the Samoa Passage. J. Mar. Res. 52, 177–195 (1994)
Sclater, J. G. & Parsons, B. Oceans and continents: similarities and differences in the mechanisms of heat loss. J. Geophys. Res. 85, 11535–11552 (1981)
Joyce, T. M., Warren, B. A. & Talley, L. D. The geothermal heating of the abyssal subarctic Pacific Ocean. Deep-Sea Res. 33, 1003–1005 (1986)
Mantyla, A. & Reid, J. L. Abyssal characteristics of the world ocean waters. Deep-Sea Res. 30, 805–833 (1983)
Johnson, G. C. & Orsi, A. H. Southwest Pacific water-mass exchanges between 1968/69 and 1990/91. J. Clim. 10, 306–316 (1997)
Gille, S. H. Warming of the southern ocean since the 1950s. Science 295, 1275–1277 (2002)
Preston-Thomas, H. The international temperature scale of 1990. Metrologia 27, 3–10 (1990)
Mantyla, A. W. Standard seawater comparison updated. J. Phys. Oceanogr. 17, 543–548 (1987)
Aoyama, M., Joyce, T., Kawano, T. & Takatsuki, Y. Standard seawater comparison up to P129. Deep-Sea Res. 49, 1103–1114 (2002)
Kawano, T., Takatsuki, Y., Imai, J. & Aoyama, M. Seawater and quality evaluation of the standard seawater supplied in a bottle. [In Japanese with English abstract]. J. Jpn Soc. Mar. Surv. Tech. 13, 11–18 (2001)
Reid, J. L. On the total geostrophic circulation of the Pacific Ocean: flow patterns, tracers and transports. Prog. Oceanogr. 39, 263–352 (1997)
Acknowledgements
We thank the officers and crew of the three research vessels (RV Kaiyo-maru of JFA, RV Mirai of JAMSTEC, and CCGS John P. Tully) and all technical assistants. The Canadian contribution was funded by the Strategic Science Fund of the Department of Fisheries and Oceans, and the Japanese contributions were funded by the Promotional Foundation for Science and Technology of the Science and Technology Agency of Japan (now known as the Ministry of Education, Culture, Sports, Science and Technology).
Author information
Authors and Affiliations
Corresponding authors
Ethics declarations
Competing interests
The authors declare that they have no competing financial interests.
Rights and permissions
About this article
Cite this article
Fukasawa, M., Freeland, H., Perkin, R. et al. Bottom water warming in the North Pacific Ocean. Nature 427, 825–827 (2004). https://doi.org/10.1038/nature02337
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/nature02337
This article is cited by
-
Ocean state estimations for synthesis of ocean-mixing observations
Journal of Oceanography (2021)
-
The use of tidally induced vertical-mixing schemes in simulating the Pacific deep-ocean state
Journal of Oceanography (2021)
-
Global mapping of 10-day differences of temperature and salinity in the intermediate layer observed with Argo floats
Journal of Oceanography (2021)
-
Wind-driven decadal sea surface height and main pycnocline depth changes in the western subarctic North Pacific
Progress in Earth and Planetary Science (2019)
-
Ultra high-resolution seawater density sensor based on a refractive index measurement using the spectroscopic interference method
Scientific Reports (2019)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.