Eddies

Not to be confused with your friend, an eddy in the ocean is a swirling of the currents. They are often smaller whirlpools and can travel long distances before disappearing. Eddies are crucial to regulating ocean temperatures by transporting heat and water long distances. They can also pick up nutrients that one would normally find on the ocean floor and transport them elsewhere thereby helping to regulate marine ecosystems. An eddy can be a few centimeters or be several hundred kilometers in diameter, and it is often hard to tell if there is an eddy present using the naked eye. Depending on the type of eddy it can either be a few centimeters above or below the waters around it.

There are many types of eddies. There are cyclonic and anticyclonic eddies, cyclonic having water that travels counter clockwise and anticyclonic eddies that circle clockwise. There are also mesoscale eddies that range from 10-500 kilometers. There are even further distinctions among them.

We learned of their existence in the 1960’s through the studying of drifters and satellite images of sea surface temperatures. In modern times, we use instruments like satellites to measure the sea surface height and radar to keep track of and study larger eddies.