Koeppen’s Climate classification India Upsc

Koeppen recognized five major climatic groups, four of which are based on temperature and one on precipitation.

• A (tropical)
• B (dry)
• C (temperate)
• D (continental)
• E (polar)

Koeppen’s classification of climate developed by V.Koeppen. This classification identified a close relationship between the climate and the distribution of vegetation. V.Koeppen selected some values of temperature, precipitation and related them to the distribution of vegetation, and used these values for classifying the climates.

This classification is an empirical classification that is based on mean annual, mean data of temperature, and precipitation data. In this classification, Koeppen introduced the use of capital and small letters to designate climatic types and groups.

Koeppen’s classification is modified over time after it is introduced in 1918. This classification is still in use and it is the most popular one. By this classification, there are 5 Major Climatic groups. Out of these five, four of them are temperature and one is precipitation based.

The capital letters: A, C, D, and E delineate humid climates and B is a dry climate. The climatic groups are further subdivided into types. The types are designated by small letters. The types are based on the seasonality of temperature characteristics and precipitation.

The seasons of dryness are designated by small letters such as f, m, w, and s. Where

f – No Dry Season

m – monsoon climate

w – winter dry season

s – summer dry season

The small letters a, b, c, and d refer to the degree of severity of temperature. The B-Dry Climates are then subdivided using the capital letters S for Stepple or Semi-Arid and W for deserts. The distribution of climatic groups is shown below:

A – Tropical Humid

• Tropical Wet (Af) – No dry season
• Tropical Monsoon (Am) – Monsoonal, short dry season
• Tropical Wet and dry (Aw) – Winter dry season

B – Dry Climate

• Subtropical steppe (BSh) – Low Lattitude semi arid or dry
• Subtropical dessert (BWh) – Low-Lattitude arid or dry
• Mid-lattitude steppe (BSk) – Mid-Lattitude semi arid or dry
• Mid-lattitude dessert (BWk) – Mid-Lattitude arid or dry

C-Warm Temperate (Mid-Lattitude) Climates

• Humid subtropical (Cfa) – No dry season, warm summer
• Mediterranean (Cs) – Dry Hot summer
• Marine West Coast (Cfb) – No dry season, warm and cool summer

D-Cold Snow-Forest Climates

• Humid Continental(Df) – No dry season, severe winter
• Subarctic(Dw) – Winter dry and very severe

E-Cold Climates

• Tundra (ET) – No true summer
• Polar Ice Cap (EF) – Perennial Ice

H-Highland

• Highland (H) – Highland with snow cover

Group A: Tropical Humid Climates

This climate exists between the Tropic of Cancer and the Tropic of Capricorn. In Tropical humid climates, the sun is overhead throughout the year and there is the presence of Inter-Tropical Convergence Zone (ITCZ).

This makes the climate hot and humid. Also, in this region, the annual range of temperature is very low, and annual rainfall is high. The tropical group is divided into three types name:

• Af – Tropical wet Climate
• Am – Tropical Monsoon Climate
• Aw – Tropical Wet and dry Climate

Af – Tropical Wet Climate

This climate is found in regions near the equator. Ex: Amazon Basin in South America, Western Equatorial Africa, and the islands of East Indies. These regions receive good rainfall every month of the year. Also, there are thundershowers in the afternoon.

The temperature is uniformly high and the annual range of temperature is negligible. The maximum temperature on any day is around 30°C while the minimum temperature is around 20°C.

This region is characterized by tropical evergreen forest with dense canopy cover. Also, a huge variety of biodiversity is found in this climatic region.

Tropical Monsoon Climate (Am)

This climate is found over the Indian sub-continent. Some of the other regions having Tropical Monsoon Climate (Am) are the North-Eastern Part of South America and Northern Australia. In this region, heavy rainfall occurs mostly in summer and has dry winter.

Tropical Wet and Dry Climate (Aw)

This climate is found in the north and south of Af-type climate regions. This borders with a dry climate on the western part of the continent and Cf or Cw on the eastern part. Extensive Aw climate is found in the north and south of Amazon forest in Brazil and adjoining part of Bolivia and Paraguay in South America, Sudan, and south of Central Africa.

The annual rainfall in Aw climate is less than Af and Am climate types and is variable also. The wet season is shorter and the dry season is longer. Also, the drought is more severe. In this climatic zone, the temperature is high throughout the year and the diurnal range of temperature is the greatest in the dry season.

Deciduous forest and tree-shredded grasslands are found in this Aw climate.

Dry Climates: B

This climate is characterized by very low rainfall. As a result, this region does not receive adequate rainfall for the growth of plants. These climates cover a large area of the earth, that extends over the large latitudes from 15° – 60° north and south of the equator.

At the low latitudes from 15° – 30°, where is an area of subtropical high? Here the subsidence and inversion of temperature do produce any precipitation. The western margin of the continents, adjoining the cold current, particularly over the west coast of South America.

These climates extend more towards the equator and occur on the coastland. In middle latitudes,
from 35° – 60° north and south of the equator. Also, this climate is confined to the interior of continents where there are maritime humid winds and do not reach.

Also found in the areas surrounded by mountains.

B(Dry Climate is divided into Steppe or Semi-Arid Climate (BS) and desert climate (BW). This climate is further subdivided as subtropical steppe (BSh) at latitudes from 15° – 35° and mid-latitude steppe (BSk) and mid-latitude desert (BWk) at latitudes between 35° – 60°.

Subtropical Steppe (BSh) and Subtropical Desert (BWh) Climates

Subtropical steppe (BSh) and subtropical desert (BWh) have common characteristics in precipitation and temperature. It is located in the transition zone between humid and dry climates, subtropical steppes get slightly more rainfall than the desert.

This rainfall is good enough for the growth of sparse grasslands. This rainfall in both climates is highly variable. This differential rainfall affects life in the steppe more than in the desert. This causes frequent famines.

In the desert, there are short intense thundershowers in deserts. These showers are ineffective in retaining soil moisture. The Summer experiences maximum temperature. Fog is common in coastal deserts bordering cold currents.

Al Aziziyah, recorded the highest shade temperature of 58° C. Also the annual and diurnal ranges of temperature are also high.

Warm Temperate (Mid-Latitude) Climates-C

This climate extends from 30° – 50° of latitude, particularly eastern and western margins of the continents. This climate has warm summers with mild winters. This climate is grouped into four types:

• Humid Subtropical i.e Dry in Winter and Hot in Summer (Cwa)
• Mediterranean (Cs)
• Humid Subtropical i.e No dry season and mild winter (Cfa)
• Marine West Coast Climate (Cfb)

Humid Subtropical Climate (Cwa)

This climate occurs poleward of Tropic of Cancer and Capricorn. It is mainly found in North Indian Plains and South China interior plains. This climate is the same as the Aw climate except for the temperature in winter is warm.

Mediterranean Climate (Cs)

Mediterranean climate found around Mediterranean sea. It is along the west coast of the continents in the subtropical latitudes between 30° – 40° latitudes. Example: Central California, Central Chile, along the coast in South Eastern and South Western Australia.

These regions are under the direct influence of a subtropical high in summer and also under the direct influence of westerly wind in winter. Here monthly average temperature in summer is around 25° C and in winter it is below 10°C.

And also the annual rainfall is between 35 to 90 cm.

Humid Subtropical (Cfa) Climate

This climate type exists in the eastern parts of the continent in subtropical latitudes. Here the air masses are usually unstable. As a result, it causes rainfall throughout the calendar year.

Example: Eastern US, South and Eastern China, Southern Japan, North-eastern Argentina, coastal South Africa, and east coast Australia.

In these regions, the annual rainfall ranges from 75-150 cm. Also here common things are thunderstorms in Summer and also frontal precipitation in winter. Here the mean monthly temperature in summer is around 27°C and in winter it varies from 5°-12° C.

The daily range of temperature is small.

Marine West Coast Climate (Cfb)

This climate is located poleward from the Mediterranean climate on the west coast of the continent. Example: North-Western Europe, West Coast of North America, North of California, Southern Chile, Southeastern Australia, and New Zealand.

Because of the influence of the sea, the temperature is moderate. In Winter, the temperature is warmer than for its latitude. The average temperature in the summer is between 15°-20° C. The average temperature in Winter is 4°-10°C.

Also, the annual and daily ranges of temperature are very little. Rainfall occurs throughout the year and it ranges 50-250 cm.

Cold Snow Forest Climates (D)

These climates are found in the large continental area in the northern hemisphere between 40°-70°. Example North Latitudes in Europe, Asia, and North America. This climate type is divided into two types:

• Df – Cold Climate with humid winter
• Dw – Cold Climate with Dry winter

Here the severity of winter is more in higher latitudes.

Cold Climate with Humid Winters (Df)

This occurs poleward of the marine west coast and mild latitude steppe. The winters in these areas are cold and snowy. And also frost-free season is very short.

Also, the annual temperature range is high. Here the weather changes are sudden, unexpected, and also short. The winters are more severe poleward.

Cold Climate with Dry Winters (Dw)

This climate occurs mostly in Northeastern Asia. The winters are anti-cyclone. Its weakens in summer sets in monsoon, reversal of wind in this region. In Polewards, the temperature in summer is low. In the winters, the temperature is extremely low.

Most locations experience, below freezing point temperature for almost seven months in a year. Precipitation occurs in the summer and the annual precipitation is very low and it is between 12-15 cm.

Polar Climates (E)

This climate exists poleward, which is beyond 70° latitude. Polar climates are of two types:

• Tundra(ET)
• Ice Cap (EF)

Tundra Climate (EF)

The ice cap climate (EF), is found over interior Greenland and Antarctica. The temperature is below freezing point even in the summer. Also, this area receives very precipitation.

The ice sheet breaks, because of the accumulation of snow and ice and the mounting pressure. These ice sheets move as icebergs, floats in the Arctic and Antarctic waters.

Tundra Climate (ET)

In this climate their different types of vegetation such as low-growing mosses, lichens, and flowering plants. This region has permafrost and the soil is frozen permanently. The climate has only a short growing season.

The water logging supports only low-growing plants. The tundra regions have a very long duration of daylight, during the summer.

Highland Climates (H)

This climate is found in high climates. Here are there occurs large changes in mean temperature that occur over short distances. The precipitation types and the intensity of precipitation vary spatially across the high lands.

Also, there is vertical zonation of layering of climatic types with elevation in the mountain.

References

• https://ncert.nic.in/ncerts/l/kegy212.pdf