Winds and gravity start water moving, but the currents that form don't flow parallel to the wind or straight down the steepest surface. This gyre covers most of the northern Pacific Ocean. The Antarctic Circumpolar Current is situated in the Southern Ocean and constantly circles around Antarctica because there are no land masses to interrupt the currents. The Great Pacific Garbage Patch is the world's largest collection of floating trash—and the most famous.
It cannot be seen from space, as is often claimed. Ekman transport occurs when ocean surface waters are influenced by the friction force acting on them via the wind. As the wind blows it casts a friction force on the ocean surface that drags the upper m of the water column with it. Gyres are caused by the Coriolis effect. Because the Earth is rotating, ocean currents in the northern hemisphere tend to move in a clockwise direction and currents in the southern hemisphere in an anti-clockwise direction.
Ekman layer, a vertical region of the ocean affected by the movement of wind-driven surface waters. This layer, named for the Swedish oceanographer V. Walfrid Ekman, extends to a depth of about metres about feet. The vertical motion refers to tides. Ocean currents are the continuous flow of huge amount of water in a definite direction while the waves are the horizontal motion of water.
Water table, also called groundwater table , upper level of an underground surface in which the soil or rocks are permanently saturated with water.
Also called the West Wind Drift. The Coriolis effect makes storms swirl clockwise in the Southern hemisphere and counterclockwise in the Northern Hemisphere.
Monsoon usually refers to the winds of the Indian Ocean and South Asia, which often bring heavy rains. Also called thermohaline circulation. Also called an autotroph. Regions are the basic units of geography. The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.
Caryl-Sue, National Geographic Society. Department of Commerce DOC. All Rights Reserved. For information on user permissions, please read our Terms of Service.
If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher.
They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource. If a media asset is downloadable, a download button appears in the corner of the media viewer.
If no button appears, you cannot download or save the media. Text on this page is printable and can be used according to our Terms of Service. Any interactives on this page can only be played while you are visiting our website.
You cannot download interactives. The weather you encounter day to day depends on where you live. Places around the Equator experience warm weather all year round, but experience alternate periods of rainy and dry seasons. Places near lakes may experience more snow in the winter, whereas places on continental plains may be more prone to hail, thunderstorms, and tornados in the summer.
Learn more about regional climates with this curated resource collection. Plastic is ubiquitous in our everyday lives. Some plastics we can reuse or recycle—and many play important roles in areas like medicine and public safety—but other items, such as straws, are designed for only one use.
In fact, more than 40 percent of plastic is used only once before it is thrown away, where it lingers in the environment for a long, long time. It often breaks down into smaller and smaller particles, called microplastics, which can be ingested by both animals and people.
Fortunately, there are things we can do to help—like stop using plastic bags, straws, and bottles, recycling when we can, and disposing of waste properly. Use these classroom resources to teach about ocean plastics and check back for more coming later this year! Marine debris is litter that ends up in oceans, seas, and other large bodies of water.
Marine debris is litter that ends up in the ocean, seas, and other large bodies of water. In the Northern Hemisphere, to the right. In the Southern Hemisphere to the left. Related questions How do humans use ocean currents to our advantage? What are ocean currents? How does ocean currents affect the earth?
Because there is little in the way of continental land masses between o south, the surface current created by the westerly winds can make its way completely around the Earth, creating the Antarctic Circumpolar Current ACC or West Wind Drift WWD that flows from west to east Figure 9.
The Antarctic Circumpolar Current is the only current that connects all of the major ocean basins, and in terms of the amount of water that it transports, it is the largest surface current on Earth. Above 60 o latitude the prevailing winds are the polar easterlies , which create a current flowing from east to west along the edge of the Antarctic continent, the East Wind Drift or the Antarctic Coastal Current. The Antarctic Circumpolar Current creates the southern boundary for all of the Southern Hemisphere gyres.
Not all of the equatorial water that is moved westward by the trade winds and reaches the continents gets transported to higher latitudes in the gyres, because the Coriolis Effect is weakest along the equator. Instead, some of the water piles up along the western edge of the ocean, and then flows eastward due to gravity, creating narrow Equatorial Countercurrents between the North and South Equatorial Currents Figure 9.
Some of this water also moves east as equatorial undercurrents that flow at depths between m, underneath the Equatorial Currents. Skip to content In the previous chapter the major wind patterns on Earth were derived.
0コメント