The water of the ocean surface moves in a regular pattern called surface ocean currents. the currents are named. In this map, warm currents are shown in red and cold currents are shown in blue.
Click on image for full size
Windows to the Universe
Surface Ocean Currents
The water at the ocean surface is moved primarily by winds that blow in certain patterns because of the Earthís spin and the Coriolis Effect. Winds are able to move the top 400 meters of the ocean creating surface ocean currents.
Surface ocean currents form large circular patterns called gyres. Gyres flow clockwise in Northern Hemisphere oceans and counterclockwise in Southern Hemisphere oceans because of the Coriolis Effect.
creating surface ocean currents. Near the Earthís poles, gyres tend to flow in the opposite direction.
Surface ocean currents flow in a regular pattern, but they are not all the same. Some currents are deep and narrow. Other currents are shallow and wide. Currents are often affected by the shape of the ocean floor. Some move quickly while others move more slowly. A current can also change somewhat in depth and speed over time.
Surface ocean currents can be very large. The Gulf Stream, a surface current in the North Atlantic, carries 4500 times more water than the Mississippi River. Each second, ninety million cubic meters of water is carried past Chesapeake Bay (US) in the Gulf Stream.
Surface ocean currents carry heat from place to place in the Earth system. This affects regional climates. The Sun warms water at the equator more than it does at the high latitude polar regions. The heat travels in surface currents to higher latitudes. A current that brings warmth into a high latitude region will make that regionís climate less chilly.
Surface ocean currents can create eddies, swirling loops of water, as they flow. Surface ocean currents can also affect upwelling in many places. They are important for sailors planning routes through the ocean. Currents are also important for marine life because they transport creatures around the world and affect the water temperature in ecosystems.
Shop Windows to the Universe Science Store!
The Summer 2010 issue of The Earth Scientist
, available in our online store
, includes articles on rivers and snow, classroom planetariums, satellites and oceanography, hands-on astronomy, and global warming.
You might also be interested in:
Wind is moving air. Warm air rises, and cool air comes in to take its place. This movement creates different pressures in the atmosphere which creates the winds around the globe. Since the Earth spins,...more
A gyre is another name for a swirling vortex. Ocean gyres are large swirling bodies of water that are often on the scale of a whole ocean basin or 1000ís of kilometers across (hundreds to thousands of...more
There are places in the ocean where water from the deep sea travels up to the surface. These are called areas of upwelling. The deep waters can have a large influence upon life in the ocean and the climate...more
A team of researchers from the Sea Education Association (SEA), Woods Hole Oceanographic Institution (WHOI), and the University of Hawaii (UH) has conducted a study of plastic debris in the ocean based...more
The majority of the world's population does not live in the Arctic. But even if you don't live in the Arctic, it is very important to understand how the Arctic Ocean works because it has an impact on surrounding...more
The Southern Ocean is a bit different. Many mapmakers do not even recognize it as an ocean. The Southern Ocean (sometimes known as the Antarctic Ocean or South Polar Ocean) surrounds Antarctica in the...more
The Atacama Desert is one of the driest places on Earth. The Atacama is in the country of Chile in South America. In an average year, much of this desert gets less than 1 millimeter (0.04 inch) of rain!...more