The Pacific Equatorial Undercurrent in three generations of global climate models and glider observations
Karnauskas, Kristopher B.
Jakoboski, Julie K.
Johnston, T. M. Shaun
Owens, W. Brechner
Rudnick, Daniel L.
Todd, Robert E.
MetadataShow full item record
Keywordequatorial Pacific Ocean; Equatorial Undercurrent; global climate models; underwater gliders
The Equatorial Undercurrent (EUC) is a vital component of the coupled ocean‐atmosphere system in the tropical Pacific. The details of its termination near the Galápagos Islands in the eastern Pacific have an outsized importance to regional circulation and ecosystems. Subject to diverse physical processes, the EUC is also a rigorous benchmark for global climate models (GCMs). Simulations of the EUC in three generations of GCMs are evaluated relative to recent underwater glider observations along 93°W. Simulations of the EUC have improved, but a slow bias of ~36% remains in the eastern Pacific, along with a dependence on resolution. Additionally, the westward surface current is too slow, and stratification is too strong (weak) by ~50% above (within) the EUC. These biases have implications for mixing in the equatorial cold tongue. Downstream lies the Galápagos, now resolved to varying degrees by GCMs. Properly representing the Galápagos is necessary to avoid new biases as the EUC improves.
Author Posting. © American Geophysical Union, 2020. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 125, (2020): e2020JC016609, doi:10.1029/2020JC016609.
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Suggested CitationKarnauskas, K. B., Jakoboski, J., Johnston, T. M. S., Owens, W. B., Rudnick, D. L., & Todd, R. E. (2020). The Pacific Equatorial Undercurrent in three generations of global climate models and glider observations. Journal of Geophysical Research: Oceans, 125, e2020JC016609.
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