This view shows the normal temperature and sea level along the equator. Temperatures are higher in the western Pacific, so the thermocline slopes downward to the west.
El Niño Phase
During El Niño, ocean temperatures and sea level in the eastern Pacific are higher than normal. The thermocline has flattened out, indicating a more even distribution of warm water across the ocean.
La Niña Phase
During La Niña, temperatures and sea level are higher than normal in the western Pacific Ocean and lower than normal in the eastern Pacific.