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Bottom water warming in the North Pacific Ocean
Masao Fukasawa1, Howard Freeland, Ron Perkin
1Ocean Observation and Research Department, Japan Marine Science and Technology Centre, Yokosuka, 237-0061, Japan. fksw@jamstec.go.jp
Nature
|February 27, 2004
Summary
Deepest ocean waters in the North Pacific have significantly warmed, indicating detectable changes even in insulated water masses. This finding has implications for understanding ocean circulation and climate change.
Area of Science:
- Oceanography
- Climate Science
- Geophysics
Background:
- Observing changes in deep ocean waters is challenging due to small signal magnitudes.
- Temporal changes in deep water properties are crucial for understanding ocean transport and thermohaline circulation.
Purpose of the Study:
- To compare deep North Pacific Oceanographic data from 1985 and 1999.
- To detect and analyze changes in the properties of deep ocean waters across the North Pacific basin.
Main Methods:
- Utilized data from a trans-Pacific oceanographic survey conducted in 1985.
- Compared these historical data with a repeated survey from 1999.
- Analyzed temperature and property changes in deep water masses.
Main Results:
- Significant warming detected in the deepest waters of the North Pacific Ocean.
- Warming observed across the entire width of the ocean basin.
- Changes in deep water properties are now measurable, even in isolated water masses.
Conclusions:
- Deep ocean warming is occurring in the North Pacific, challenging previous assumptions about insulation.
- These findings suggest detectable impacts on water masses previously thought to be isolated from atmospheric influence.
- The observed changes provide new constraints on ocean water transport and global thermohaline circulation patterns.
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