Increased ocean heat transports and warmer climate
- NASA Goddard Space Flight Center, New York, NY (USA)
- Columbia Univ., Palisades, NY (USA)
The authors investigated the effect of increased ocean heat transports on climate in the Goddard Institute for Space Studies (GISS) general circulation model (GCM). The warming is driven by the decreased sea ice/planetary albedo, a feedback which would appear to be instrumental for producing extreme high-latitude amplification of temperature changes. Resulting hydrologic and wind stress changes suggest that qualitatively the increased transports might be self-sustaining. As such, they would represent a possible mechanism to help account for the high-latitude warmth of climates in the Mesozoic and Tertiary, and decadal-scale climate fluctuations during the Holocene, as well as a powerful feedback to amplify other climate forcings. It is estimated that ocean transport increases of 50-70% would have been necessary to reproduce the warmth of various Mesozoic (65-230 m.y. ago) climates without changes in atmospheric composition, while the 15% increase used in these experiments would have been sufficient to reproduce the general climatic conditions of the Eocene (40-55 Ma). A companion experiment indicates that increased topography during the Cenozoic (0-65 Ma) might have altered the surface wind stress in a manner that led to reduced heat transports; this effect would then need to be considered in understanding the beginning of ice ages. The large high-latitude amplification associated with ocean heat transport and sea ice changes differs significantly from that forecast for increased trace gases, for which water vapor increase is the primary feedback mechanism. The different signatures might allow for discrimination of these different forcings; e.g., the warming of the 1930s looks more like the altered ocean heat transport signal, while the warming of the 1980s is more like the trace gas effect.
- OSTI ID:
- 5504494
- Journal Information:
- Journal of Geophysical Research; (United States), Vol. 96:D4; ISSN 0148-0227
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
54 ENVIRONMENTAL SCIENCES
ATMOSPHERIC CIRCULATION
GENERAL CIRCULATION MODELS
OCEANIC CIRCULATION
ALBEDO
CENOZOIC ERA
CLIMATES
HEAT TRANSFER
HEATING
HYDROLOGY
ICE
LATITUDE EFFECT
MESOZOIC ERA
OCEANOGRAPHY
PALEOCLIMATOLOGY
QUATERNARY PERIOD
SEAS
SEAWATER
TERTIARY PERIOD
TOPOGRAPHY
VARIATIONS
WIND
ENERGY TRANSFER
GEOGRAPHICAL VARIATIONS
GEOLOGIC AGES
HYDROGEN COMPOUNDS
MATHEMATICAL MODELS
OXYGEN COMPOUNDS
PALEONTOLOGY
SURFACE WATERS
WATER
580000* - Geosciences
540310 - Environment
Aquatic- Basic Studies- (1990-)
540110