What happens when a wave you can barely see travels thousands of miles across the Pacific and quietly raises sea levels along the coast?

In this episode of The Climate Translation, Dr. Mac explains Kelvin waves: what they are, how they form, and why they are closely connected to the powerful El Niño developing across the Pacific. These enormous pulses of warm water can deepen the warm upper layer of the ocean, raise sea levels by several inches, and then turn north along the coast of the Americas after reaching South America.

The episode also explores what that means for places along the West Coast, where elevated water levels can persist for weeks or even months and combine with high tides, storms, and large waves to increase coastal flooding and erosion. And as long-term sea-level rise co ...