An Equatorial Ocean Bottleneck in Global Climate Models Journal Article


Authors: Karnauskas, Kristopher B.; Johnson, Gregory C.; Murtugudde, Raghu
Article Title: An Equatorial Ocean Bottleneck in Global Climate Models
Abstract: The Equatorial Undercurrent (EUC) is a major component of the tropical Pacific Ocean circulation. EUC velocity in most global climate models is sluggish relative to observations. Insufficient ocean resolution slows the EUC in the eastern Pacific where nonlinear terms should dominate the zonal momentum balance. A slow EUC in the east creates a bottleneck for the EUC to the west. However, this bottleneck does not impair other major components of the tropical circulation, including upwelling and poleward transport. In most models, upwelling velocity and poleward transport divergence fall within directly estimated uncertainties. Both of these transports :play a critical role in a theory for how the tropical Pacific may change under increased radiative forcing, that is, the ocean dynamical thermostat mechanism. These findings suggest that, in the mean, global climate models may not underrepresent the role of equatorial ocean circulation, nor perhaps bias the balance between competing mechanisms for how the tropical Pacific might change in the future. Implications for model improvement under higher resolution are also discussed.
Keywords: CIRCULATION; PACIFIC-OCEAN; DYNAMICS; CURRENTS; SENSITIVITY; VARIABILITY; SST; TROPICAL PACIFIC; TELECONNECTIONS; GALAPAGOS-ISLANDS
Journal Title: Journal of Climate
Volume: 25
Issue: 1
ISSN: 0894-8755
Publisher: American Meteorological Society  
Publication Place: BOSTON; 45 BEACON ST, BOSTON, MA 02108-3693 USA
Date Published: 2012
Start Page: 343
End Page: 349
DOI/URL:
Notes: PT: J; TC: 0; UT: WOS:000299130000021