Climatic Belts.

There are 13 climatic belts. They have different temperature conditions and air masses. Climatic belts are divided into main and transitional.

 

Main.	Transitional.
Equatorial 2 Tropical 2 Temperate Arctic Antarctic	2 Subequatorial 2 Subtropical Subarctic Subantarctic

 

- Equatorial climatic belt. In equatorial climatic belt all year round predominant equatorial air masses. Atmospheric pressure is low, temperature is high, the sum of rainfalls is large. There is 1 season.

- Tropical climatic belt. In tropical climatic belt predominant tropical air masses, high atmospheric pressure, temperature is high. Summer is cooler. It’s seldom rain. There are 2 seasons.

- Temperate climatic belt. In temperate climatic belt predominant temperate air masses, west winds. The sum of rainfalls is different in different places. There are 4 seasons.

- Arctic and Antarctic climatic belts. They are the coldest climatic belts. Climate here is severe. Atmospheric pressure is high, predominant arctic and antarctic air masses.

The transitional climatic belts are situated between the main climatic belts.

Natural Complexes.

Natural complexis a plot of the surface of the Earth, which differs with peculiaritiesof natural components. All the natural components are connected with each other. If we change one of them, the other changes too. The difference of natural complexes depends on mountain systems, relief and climate. Natural complex can be large or small. Continents are the largest natural complexes on the dry land.

Natural complexes form in the oceans too. They consist of the following components: water with soluble gases, plants, animals, rocks and the relief of the bottom. The world ocean is a huge natural complex. We can also find other natural complexes: oceans, seas, bays, straits, rivers, lakes and so on. There are many natural complexes both in the oceans and on the dry land.

Natural complexes on the dry land and in the oceans change in different directions: from the north to the south, from the coastlines far into the land, from the foot of the mountain to its top. It depends on climate, the structure of the earth crust, peculiarities of water masses and other reasons, which influence on the formation of natural complexes.

Natural zoneis a large natural complex, which has common temperatureconditions, moisture, soils, vegetation and animal world. Natural zones are on the dry land and in the oceans too.

 

Natural zones on the continent	Natural belts of the World Ocean
Arctic deserts Tundra and forest–tundra Taiga Mixed and deciduous forests Steppes and forest-steppes Deserts and semi-deserts Savannahs and rare forests Tough evergreen forests and shrubs Monsoon forests Wet evergreen forests High altitude zone	North pole North sub pole North temperate North subtropical North tropical Equatorial South tropical South subtropical South temperate South sub pole South pole

 

High Altitude Zone. The Andes.

We can see the changing of natural zones not only on the continents and oceans, but in the mountains as well. Temperature, pressure and rainfalls change on the height over the sea level. We can find different natural belts in the mountains.

In the mountains the natural zones change one goes up the slopes. At the foot of the mountains there is a natural zone peculiar for the surrounding plain. For example, near the equator there are equatorial forests, till altitude 1.200-1.500 m above sea level. Then come the mountain forests. The temperature here is + 12,+20C, rainfalls- 3.000 mm.Treefern, bamboo, cinchonatree grow here. At the height of 2.800- 3.800 m there are alpine forests. Alpine meadows re situated at the height of 4.500 m. Perennial snow and glaciers are at the height of 4.500m and more. The animal life is not rich here. We can see vicuna, chinchilla, condor.

 

2.The World Ocean.

All the planets of the Solar System but the Earth have no oceans. Water occupies ¾ of the surface of the globe, so the continents look like big islands in the World Ocean. The role of the ocean in the life of people increases. It becomes the source of minerals, water, food, energy.

Oceanic water is very salty. The salts come into the ocean with the river waters mainly. Oceanic water contains salts, gasses and insoluble particles. Saltiness of water depends on rainfalls and evaporation.

In the World Ocean there are four types of water masses:

· equatorial;

· tropical;

· temperate;

· polar (arctic and antarctic).

There is an interaction between water masses and atmosphere. They exchange warmth, moisture and gasses.

Movement of the water masses in the World Ocean takes place on the surface and near the bottom. There are some reasons influencing the formation of water masses:

1. the warmth of the Sun;

2. winds;

3. different t^o;

4. different saltiness.

 

The direction of the oceanic currents depend on:

· the direction of the winds;

· rotation of the Earth;

· relief of the bottom;

· coastlines of the continents.

 

The oceanic currents may be:

ü permanent;

ü periodic;

ü wind currents;

ü flow currents;

ü surface;

ü deep;

ü near the bottom.

 

 

There are warm currents and cold currents.

Warm currents	Cold currents
Gulf Stream North Atlantic Curocio Monsoon South Trade North Trade Brazilian North Pacific	Californian Peruvian Bengel Canarian Western Winds

The World Ocean is very rich. People go fishing. They gather seaweeds for food and corals for jewelry. They also use minerals

Life in the World Ocean.

There are many different living organisms in the World Ocean. They live on the surface, deep in water and on the bottom. Most of them live in the surface layer, which is 160 meters deep, because the sunbeams warm and lighten the water there. Many animals live not far from the coastlines of the continents and islands. Plankton lives on the surface and is carried by currents. There are also many active living organisms as fish, dolphins, whales, seals, sharks, turtles and so on. Different corals, worms, mollusks live on the bottom.

The distribution of living organisms in the surface layer depends on the climatic zone. There is little plankton in polar waters. In subarctic and subantarctic climatic belts the amount of plankton is great. Many fishes and whales come here to feed. In temperate climatic zone, there is a lot of plankton too. In subtropical and tropical belts, water is very warm and because of that is rather salty. Many corals live there. They build coral reefs and islands. There is no plankton there. Near the equator, there is usually no plankton as well, but in some places on the border of currents, you can see big amount of it. That is why many fishes live in equatorial zone

 

 

Ecological Problems of the World Ocean.