Sea surface temperature temperature pattern is when warm water spreads from the west Pacific and the Indian Ocean to the east Pacific. It takes the rain with it, causing extensive drought in the western Pacific and rainfall in the normally dry eastern Pacific. El Niño's warm rush of nutrient-poor tropical water, heated by its eastward passage in the Equatorial Current, replaces the cold, nutrient-rich surface water of the Humboldt Current. When El Niño conditions last for many months, extensive ocean warming and the reduction in Easterly Trade winds limits upwelling of cold nutrient-rich deep water and its economic impact to local fishing for
The Blob (Pacific Ocean) ultimate cause of the phenomenon, but states "there's no doubt that this anomaly in sea surface temperature is very meaningful". Sea surface temperature anomalies are a physical indicator which adversely affect the zooplankton (mainly copepods) in the Northeast Pacific and specifically in the Coastal Upwelling Domain. Warm waters are much less nutrient-rich than the cold upwelling waters which were the norm till recently off the Pacific Coast. This results in reduced phytoplankton productivity with knock on effects on the zooplankton which feed on it and the higher levels of the food chain. The Northwest Fisheries Science Center, Seattle has predicted