Final answer:
El Niño circulation is characterized by warming off the coast of Ecuador, leading to changes in weather patterns and a decrease in ocean upwelling.
Step-by-step explanation:
El Niño circulation is characterized by warming off the coast of Ecuador. El Niño is a significant part of the ENSO, where warm ocean water develops in the central and east-central equatorial Pacific, which leads to high air pressure in the western Pacific, and low air pressure in the eastern Pacific. These changes in pressure and temperature disrupt normal weather patterns, which can lead to extreme weather events around the globe. It is also associated with a decrease in ocean upwelling, which is the rising of deep ocean waters that bring nutrients to the surface, supporting marine life. However, during El Niño events, this upwelling is weakened, affecting sea life and weather patterns.