In January 2010 sea surface heights across the cental & eastern equatorial Pacific were elevated (red), but not extremely, potentially a sign that El Niño was weaking. But in early February 2010 a strong sea level anomaly appeared NE of Australia. This swell of deep, warm water is the start of the Kelvin wave, and by late February, had spread eastward into the central Pacific & re-invigorated the current En Niño.

Centre for Spatial Environmental Research (CSER)