§ 38. Climatic zones (textbook)

§ 38. Climate Zones


Remember that distinguish air masses depending the area of their formation.


Climate Zones. Climatic zones - latitudinal band Earth surface, which have relatively homogeneous climate. Belts different from each other and air temperature prevailing air masses, which, according to its properties determine the basic features of the climate zone. Climatic zones vary from equator to the poles, ie zonal. There are seven major climatic zones: equatorialTwo TropicalTwo moderate and two Polar (Arctic and Antarctic) - One in each hemisphere. In each of them throughout the year dominates an air mass - equatorial respectively, of tropical, temperate, Arctic (Antarctic).

Between main belts in each hemisphere formed transient Climatic zones: subekvatorialnyy, subtropical and subarctic (subantarktychnyy). They are called subpoyasamy - From the Latin "sub"Means" below ", ie during the main (pidekvatorialnyy, pidtropichnyy etc.).. In transition zones by air mass changes seasons. They come from neighboring main zones: the summer air rule mass south of the main belt, and in winter - the north. For example, subekvatorialnomu equatorial belt dominates the summer air - comes humid season, the winter arrives tropical air - dry season comes. Therefore, climate subekvatorialnoho zone in summer is similar to the equatorial climate zone, and winter - to tropical.

The map of climatic zones is clearly visible that their boundaries not held strictly in parallel, and then declined to the north, then south. This is explained by the influence of third klimatotvirnohofactor - laying surface: the oceans, land, terrain, currents, ice cover.

Inside climatic zones are distinguished climate area with different types climates: Continental and sea, a peculiar climate of western and eastern coasts of continents.


Fig. Climatic zones


Main types of climate. At various territories under the same influence klimatotvirnyh factor is formed some type of climate. Type name corresponds to the name of climate climatic zone (equatorial, subtropical, tropical, temperate climate, etc..) subtype of air masses (Marine, continental climate), temperature and moisture characteristics.

У equatorial belt dominated moist equatorial air masses. The temperature high (24 ... 28 0C). Rising flow of air generated by powerful Cumulonimbus clouds, which every day brought rain with thunderstorms. Loss of large rainfall during the year (over 2000 mm) promote and trade winds that bring Oceanic humid air. Temperature and rainfall during the year almost change.

For subekvatorialnyh zones typical seasonal changes of air masses. Summer monsoon brings equatorial air and winter monsoon - tropical continental. Therefore, summer hot and humid in the equatorial belt. A winter temperature slightly decreases (20 0C), low humidity, no rain. Such a climate of wet summers and dry winters called Monsoon. Growing deciduous forest.

У Tropical zones dominate dry tropical air masses. There, high atmospheric pressure and downward airflow. The temperature in summer is very high (35 0C) decreases slightly in winter (20 0C). Very high daily amplitude oscillations (30-40 0C). Tropical air is very dry because rainfall generally little. With rainfall in this belt formed climatic region with different types of climate. Tropical desert climate (precipitation almost No, only formed abundant dew and fog) formed on western coasts of continents, which are washed by cold currents. Tropical wet climate (rain a lot - more than 1000 mm per year) reign on eastern coasts of continents, which are washed by warm currents.

У subtropical zones climate shaped by seasonal changes air masses: summer - rain, winter - temperate. Continental subtropical climate - dry, with hot summers, cold winters. On the western coasts of continents climate subtropical Mediterranean with hot, dry summers and mild wet winters. On the east coast climate monsoon(Summers are hot, wet, cool winters and dry). In the depth of the mainland climate sharply continental (Cool summers and severe winters, a little rain).

У temperate zones dominate moderate air masses and west winds, cyclones and anticyclone. There is good pronounced seasons with positive and negative temperatures in summer in winter. Precipitation falls a lot, but they are unevenly distributed: many in the west of continents, little in the hinterland, just to the east. Zone formed in different climatic region. Continental temperate type of climate (temperate sharply continental to continental) prevalent in the hinterland continents. On the western coasts of continents formed moderate sea climate, on the east - monsoon.

Subarctic і subantarktychnomu belt similarly characterized seasonal changes of air masses: summer dominated moderate, Winter - Arctic. Summer is cool (10 0C) and raw, harsh winter (-40 0C) long and little snowfall. Little rainfall - 200 mm per year. A widespread perennial frost - frost rocks at great depth (500 m). Sea climate with cool summers and mild winters observed around Arctic Ocean and Antarctica.

У Arctic (Antarctic) zone prevailing cold and dry Arctic (Antarctic) air masses. Negative air temperatures throughout the year. Very little rainfall - 100 mm per year.

Climate plays an important role in living and inanimate Nature Land. It identifies the distribution of soils, vegetation and wildlife, state of rivers, lakes, seas, glaciers.


Fig. Arctic zone


Fig. Tropical zone


Fig. Subekvatorialnyy zone


Climate map. Understand the complex formation and accommodation climates to help the Earth climate maps. They contain data on the basic elements of climate: temperature warmest and coldest months (January and July), wind direction, rainfall. The average temperature isotherms show. Individual numerals denote the lowest and highest temperatures. To show the map how much and where rain falls, the place with different annual number of different paint over colors. Their area of winds shown by arrows. The climate card can be to characterize the climate of any area.

Impact climate on humans. Weather and climate affect the living conditions of people. To different types of people have learned to climate adapt. Their housing, clothing, shoes, food - the result of such adaptations. Everyone knows that housing, clothing, shoes Hyperborean different from where she lives and in which resident dressed and uzutyy equatorial zone. Climate determines not only need to warm or cool, and and even mood.

With climate related crop and everyday work builders, pilots, sailors. Without knowledge of climate can not be properly choosing a location for dams, reservoirs and airports, to identify areas of airline and sea routes. Weather and climate affect the health and well- people. For example, people who come to work in the Arctic regions, sometimes forced to turn back, because not every body can adapt to conditions severely climate with strong winds and frost. In areas with warm maritime climate created resorts for rest and treatment.

Changes climate. If the weather observed variability, the climate is the opposite - resistance. If he changes then slowly and for a very long time - tens of thousands and millions of years. In the distant geological past climate change occurred waves: hasted then warming, then cooling. These fossils prove climate variability remains of plants and animals that existed under certain conditions, and various mountain breed. For example, coal could be formed when warm and humid climate. So it lay in Antarctica show that once there was a climate different. As a result of climate cooling that occurred about a million years ago at the Earth's ice age began. While large areas of land covered with glaciers. Ended this period of only 10-12 thousand years ago.


Questions and Tasks

1. What on Earth distinguish basic and transitional climatic zones?

2. Which air mass "moving in winter and summer subtropical and subarctic zones?

3. How does the type of climate in the temperate zone with distance from the Atlantic Ocean?

4. On climate indicators are available by climatic maps?

5. What turns impact of climate on living conditions Rights?

6. Can climate change over geological time?