An Equatorial Ocean Bottleneck in Global Climate Models Journal Article uri icon



  • 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.

publication date

  • January 1, 2012

has restriction

  • bronze

Date in CU Experts

  • November 12, 2015 7:05 AM

Full Author List

  • Karnauskas KB; Johnson GC; Murtugudde R

author count

  • 3

Other Profiles

International Standard Serial Number (ISSN)

  • 0894-8755

Electronic International Standard Serial Number (EISSN)

  • 1520-0442

Additional Document Info

start page

  • 343

end page

  • 349


  • 25


  • 1