Meridional Dipole in Eddy Activity Along Peruvian Coast During Eastern Pacific El Niño Events

Abstract Mesoscale oceanic eddies ((100)km) play a key role in regulating climate by affecting the transport of heat and water mass properties. However, most climate models struggle to simulate these eddies due to coarse horizontal resolution. Using a 120‐year ultra‐high‐resolution simulation with 1/10 horizontal ocean resolution, conducted with the Community Earth System Model, this study examines how eddy activity off Peru changes during Eastern Pacific (EP) El Niño events. The model shows a meridional dipole in eddy activity during EP El Niño, with increased energy north of ∼14S and decreased energy to the south, matching satellite‐data except for the extreme 1997/1998 El Niño. This pattern is caused by baroclinic instabilities linked to El Niño‐driven changes in the equatorial undercurrent. The study also finds a nonlinear relationship between the strength of the dipole pattern and El Niño‐related equatorial influences, providing new insights into the equatorial oceanic teleconnection along the coast of Peru.