With its own forms of underwater weather, the ocean has fronts and circulation patterns that move heat and nutrients around its basins. Changes near the surface often start with changes in the depths.
These color-coded images show the strengthening of El Niño between October and November 2009. In the November image, warm waters (indicated in red) have spread across the Pacific.
For many people, El Niño and La Niña mean floods or drought, but the events are actually a warming or cooling of the eastern Pacific Ocean that impacts rainfall. These sea surface temperature and rainfall anomaly images show the direct correlation between ocean temperatures and rainfall during El Niño and La Niña events.
These images show that the central and eastern Pacific Ocean was unusually cold in December 2010, a tell-tale sign of La Niña. The associated rainfall map shows that La Niña was impacting weather in parts of the globe.