Examining temperatures from the depths of the ocean, JPL scientists have found that lower layers of the Western Pacific and Indian Oceans grew much warmer during a decade when surface temperatures cooled.
Submerged in the Atlantic Ocean off the coast of Spain and Portugal are giant, salty whirlpools of warm water. These deep-water whirlpools are part of the ocean’s circulatory system, and they help drive the ocean currents that moderate Earth’s climate. Warm water ordinarily sits at the ocean’s surface, but the warm water flowing out of the Mediterranean Sea is so salty (and therefore dense) that when it enters the Atlantic Ocean at the Strait of Gibraltar, it sinks to depths of more than 1,000 meters (one-half mile) along the continental shelf. This underwater river then separates into clockwise-flowing eddies that may continue to spin westward for more than two years, often coalescing with other eddies to form giant, salty whirlpools that may stretch for hundreds of miles. Because the eddies originate from the Mediterranean Sea, scientists call them “Meddies.”
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.
A strip of cold water hugging the equator in the eastern tropical Pacific Ocean in mid-June may foreshadow a transition from El Niño to La Niña conditions
La Niña, the large area of cold water in the Pacific Ocean widely blamed for last summer's drought and often related to an increase in the number of hurricanes that make landfall, appears to be on its last legs.