Climates of World
The climates of World varies with different regions, local conditions and other geographic features. The classification of climates of world as suggested by Koeppen is commonly followed for studies. The major types of climate according to this system of classification are- i) Tropical Climate, ii) Dry Climate, iii) Humid Mesothermal climate, iv) Humid Microthermal climate, v) Polar Climate and vi) Highland Climate. This classification is done on the basis of mean monthly temperature, precipitation(rain), degree of aridity and special temperature characteristics.
Climates of World : Tropical Climate
This climate occurs in tropical zone, where the mean monthly temperature remains generally above 220 C. This climate do not have perceptible (rainy) winter season. The major subtypes of this climate are the tropical rainforest, tropical monsoon and tropical savanna climates.
Climates of World : Tropical Rainforest
This climate is characterized by year round precipitation and the areas support dense evergreen forests of tall trees. The basis of tall forests is the high temperature and a large amount of precipitation generally over 250 cm. The average temperature in this type of area is about 270 C. The climate of the Congo basin and Amazonia are of this type.
In this type of climate the rainfall is seasonal and generally occurs in summer and may be as high as 300 cm in favorable locations. Due to this the vegetation in these regions is of deciduous type i.e. the trees shed their leaves during the dry season. The average temperature of is about 260 C.
Climate of India
Climate of India and some neighbouring Southeast Asian countries is the best example of Tropical monsoon climates of world. Here the average temperature is about 260 C and heavy rains are observed during the monsoon period of June to Sept.
In this climate the total amount of rainfall is lesser about 160 cm. Annual average temperature is about 230 C. Due to lack of rainfall the vegetation in these regions is open thorn type forests and grasslands with occasional bunch of trees. Savanna type climate is transitional between tropical wet climates towards equator and dry climates towards poles. Parts of northern Australia, Savana regions of Africa and Venezuela are among the typical examples of the areas of this type of climate.
Climates of World : Dry Climate
The climate is characterized by lack of rains. The annual precipitation is less than the normal evaporation and no permanent streams originate from such regions. It has two major subtypes – Tropical & subtropical deserts and Tropical and subtropical steppes.
These regions have temperature of about 380 C. The average rainfall is about 25 to 40 cm. The typical areas of tropical deserts are Sahara, Atacama, Thar, Gobi, Arabian and Kalahari deserts. This type of climate covers vast area in Australia too. Most of the tropical deserts occupy western margins of continents near the tropics.
Subtropical deserts are usually in the interiors of the continents where the moisture bearing winds fail to reach. Due to lack of rainfall, these deserts have very limited plant and animal life. Thorny bushes and patches of grass are typical vegetation of these regions. The subtropical deserts are also called hot deserts.
Steppes are areas of comparatively lower temperature and slightly more precipitation. Annual average temperature is about 210 C. Rainfall is not only limited, it is also highly variable. Temperate grasses are the chief vegetation of these regions. They occupy poleward margins of tropical and subtropical deserts. Much of the precipitation of these regions is provided by cyclonic storms. American Prairies and Eurasian Steppes are major areas of these grasslands. These regions are ideally suited for cultivation of grain crops such as wheat.
Climates of World : Humid Mesothermal Climate
This climate is subdivided into three main types – the Mediterranean type, China type and West European type.
This climate is typical of western coastal parts between latitudes of 300 and 450 in both hemispheres. The annual average temperature is about 160 C with a summer average of 250 C and winter average of 100 C. Annual rainfall is 40 to 60 cm and occurs in winter, while summers are dry. The typical vegetation of these regions consists of plants which can withstand a long dry summer season. They have thick barks and deep roots. Olives, grapevine and citrus family fruits are the chief products of these regions which are also known for grain farming. Areas under the Mediterranean sea, central region of Chile, southern tip of South Africa and south western part of Australia are the chief regions of this climate.
Climates of World : China Type Climate
This climate is characterized by warm summers and cool winters, the average temperature being around 190 C and annual rainfall about 120 cm. This type of climate is experienced in eastern parts of continents in the same latitude in which Mediterranean type of climate is found. Rainfall is available throughout the year and the major areas of this type of climate are in China, Argentina, south-eastern parts of USA and the eastern coastal region of Australia.
Climates of World : West European type of Climate
This type of climate is characteristic of coastal region of Western Europe. This region extends between the latitudes of 400 and 600 N and S and includes Western Europe, parts of North America, South America, and south-eastern coastal regions of Australia. Average annual temperature is about 100 C. The summers are cool but winters are cold and the temperatures go below 100 C. There is a distinct marine influence on the climate of these regions, and the temperature even in winters remains slightly higher than the normal temperature of these latitudes. Rainfall occurs throughout the year but it is more in winter season. The cold polar air flow is common in these latitudes and the temperate cyclones provide much of the precipitation.
This type of climate is experienced in two large belts, one each in North America and Eurasia. Based on the type of forests growing there, this climate is also known as “taiga climate”. Most of the Siberian region and the high latitude areas of USA and Canada have this climate. This is characterized by cool summers and cold winters. The summer temperature is sometimes higher than 100 C, but the temperature in winter goes below freezing point and remains so for eight months. The total annual precipitation is generally below 50 cm but on account of low temperatures, this is enough to support Coniferous Forests. These forests are most important source of softwoods and fur bearing animals. Fur farming has now-a-days become one of the important activities, besides lumbering in these regions.
These climates are experienced only in Polar regions. This is characterized by severe winters and even the summers are cold. The precipitation is very low, generally below 30 cm. Due to low temperatures, vegetation is practically non-existent. Only during the short summer season some small plants grow in the areas away from polar ice caps. These regions are known for blizzards which are high velocity winds carrying ice particles with them. These regions are also called Cold Deserts and they occupy the areas of Arctic margins of North America and Eurasia and the Antarctica continent.
Climates of World : Highlands Climate
This type of climate is experienced in mountain regions of the Himalaya, Tibetan Plateau, Rockies, Andes and the Alps. The climate of such regions is significantly modified by the altitude and the aspect of slope and these regions have a variable climate. Temperature conditions vary according to the altitude and the precipitation varies according to slope.