Oceans: study ocean currents

The world ocean is one of the most mysterious phenomena. Even now it is not fully understood. Why is it unique? First of all, these are ocean currents. They play a big role in shaping the climate on the planet Earth, and are also largely responsible for the diversity of flora and fauna. Today we will get acquainted with the types of currents, the cause of their occurrence, consider examples.

It's no secret that our planet is washedfour oceans: Pacific, Atlantic, Indian and Arctic. Naturally, the water in them can not be stagnant, since this would have led to an ecological catastrophe long ago. Due to the fact that it constantly circulates, we can fully live on Earth. Below is a map of ocean currents, it clearly shows all the movements of water currents.

What is the current in the ocean?

The flow of the World Ocean is nothing more than acontinuous or periodic movement of large masses of water. Running ahead, we will immediately say that there are a lot of them. They differ in temperature, direction, depth passage and other criteria. Oceanic currents are often compared to rivers. But the movement of river flows occurs only downward under the influence of gravitational forces. But the circulation of water in the ocean is due to many different reasons. For example, wind, uneven water mass density, temperature difference, the influence of the Moon and the Sun, pressure changes in the atmosphere.

Causes

I want to start my story with the reasons thatgenerate a natural circulation of water. There is practically no exact information at present. This is explained quite simply: the system of the oceans has no clear boundaries and is in constant motion. Now the flows that are closer to the surface are studied in more depth. To date, one thing is certain that factors affecting the water circulation can be both chemical and physical.

So, let us consider the main causesocean currents. The first thing I want to highlight is the effect of air masses, that is, wind. It is thanks to him that the surface and shallow currents function. Of course, the wind does not have a relationship to the water circulation at great depth. The second factor is also not unimportant, it is the impact of outer space. In this case, the flow is due to the rotation of the planet. And finally, the third main factor that explains the causes of ocean currents is different density of water. All the streams of the World Ocean are characterized by a temperature regime, salinity and other indicators.

Directional factor

Depending on the direction of the circulation of ocean waters are divided into zonal and meridional. The first move to the west or to the east. Meridional currents go to the south and north.

There are also other species caused by tides. Such ocean currents are called tidal. They have the greatest power in shallow water in the coastal zone, in the mouths of rivers.

The currents, which do not change forces and directions,called stable, or settled. These include such as the Northern Trade- and Southern Trade-South. If the movement of the water flow varies from time to time, it is called unstable, or unsteady. This group is represented by surface currents.

Surface currents

The most notable of all are surfaceThe currents that are formed due to the influence of wind. Under the trade winds, constantly blowing in the tropics, huge streams of water form near the equator. They form the Northern and Southern equatorial (trade-wind) currents. A small part of these water masses unfolds and forms a countercurrent. The main streams deviate north or south when colliding with the continents.

Warm and cold currents

Types of ocean currents play an important role in thedistribution on the Earth of climatic zones. It is common to call warm streams of the water area, which carry water with a temperature above zero. Their movement is characterized by a direction from the equator to high geographical latitudes. This is the current of the Alaskan, Gulf Stream, Kuroshio, El Nino, and others.

Cold streams carry water in the opposite directiondirection in comparison with warm ones. Where there is a current with a positive temperature on their way, there is an upward movement of water. The largest are the California, Peru, and others.

The division of currents into warm and cold bearsconditional character. These definitions reflect the ratio of the water temperature in the surface layers to the ambient temperature. For example, if the flow is colder than the rest of the water mass, then this flow can be called cold. If on the contrary, it is considered a warm current.

The oceanic currents largely determineclimate change on our planet. Constantly mixing the water in the World Ocean, they create conditions favorable for the livelihoods of its inhabitants. And our lives directly depend on this.