La Ni̱a, 2007

- Image ID: HRJP1C
Science History Images / Alamy Stock Photo
Image ID: HRJP1C
The cooler waters of a La Ni̱a inhibit cloud growth overhead as seen in this image of the Pacific Ocean on November 8, 2007. A La Ni̱a event occurs when cooler than normal sea surface temperatures form along the equator in the Pacific Ocean, specifically in the eastern to central Pacific. The La Ni̱a we are experiencing now has a significant presence in the eastern part of the ocean. The cooler water temperatures associated with La Ni̱a are caused by an increase in easterly sea surface winds. Under normal conditions these winds force cooler water from below up to the surface of the ocean. When the winds increase in speed, more cold water from below is forced up, cooling the ocean surface.