In 1931, one of the most referred climate classification scheme was presented by Vladimir Koppen of Germany. His empirical classification was based on the analysis of annual temperature and precipitation values. As he was inspired majorly by De Candolle’s vegetative classification scheme, he incorporated vegetation as also one of the important basis. In 1936 he added, Altitude as the final basis for the classification scheme. The scholar used alphabetical symbol to denote out the types of climate prevailing in the world. These symbols were subcategorized into 3 groups precisely to detail out the characteristics of climate referred for a region.
Temperature has been the most prominent basis of the classification scheme. Out of the 6 major types of climates, 4 are based on temperature –
the ‘A’ type of climate – Tropical;
the ‘C’ type – subtropical;
the ‘D’ type – temperate and
the ‘E’ – polar type of climate.
These categories strongly represent the latitudinal divide of either hemisphere. Of these, it is ‘E’ type of climate which occupies 70° – 90° N & S is entirely detailed on temperature ground. ET – the tundra type of climate occupies the arctic coastal fringes, dominated by cP, mP and cA air masses. Winters are long and severe. There is a very short mild season which is not recognized as true summers. However it is in this mild season that surface ice thawing is experienced. The major zones of occurrence are arctic coast of N. America, Greenland coast, Arctic coast of Eurasia and Antarctica Peninsula. The EF – Forsted type of climate are the source regions of cA – cP air masses. These are recognized with vast, high ice sheets and over Polar Sea, ice of Arctic ocean. Mean temperature is always below freezing point. Temperature inversions are strongest. The strong net radiation deficit in winters at high surface altitudes intensifies the cold. Precipitation is always as snow, is small but accumulates as ablation is marginal.
The precipitation values have been used mostly to bring out the details of principal categories of climate.
‘A’ type of climate is subcategorized into 3 major groups based on precipitation amount and distribution.
Af type of climate is equatorial climate which occupies the region between 10° N to 10° S. It is dominated by warm, most maritime equatorial mE and mT air masses, yielding heavy convectional rainfall. Rainfall is copious in all the months with annual total being over 250 cm. Remarkably uniform temperature prevails throughout the year. The major regions of occurrence are Amazon lowlands, Congo basin, upper Guinea and East Indies. Am monsoonal type of climate occupies tropical east margins. Trade winds bring maritime tropical air mass from moist western sides of oceanic high pressure cells leading to heavy orographic rainfall along the coastal region. Shower activity is intensified only during high sun season. Temperatures are warm throughout the year but with marked annual cycle. The eastern sides of central and SE Brazil, Caribbean Island, Medagascar, Indo–China, Penensular India experiences this climate.
Aw – Savannah type of climate is continental interiors of tropics. The region experiences only summer rains with dry winters though amount of rain is not recognized to be more than 100cm. The savannah belt of central Africa, Carpentarian plains of Australia, Llanos of Venezuela, Campos of Brazil experiences this climate.
The ‘C’ type of climate also has been sub categorized into 3 categories.
The Cw type of climate is moist subtropical climate extending between 30–45°N and S along the east margins of continent. The mT air mass flowing out from the moist western sides of oceanic high pressure cells dominates the climatic conditions. Summer rains are quite concentrated. Winter precipitation by the mid latitude cyclones are also pronounced. Invasion of cP air mass during winters develops sub freezing conditions. The Northern Chinese plain, Piedmont (Appalachian) plains, Shikoku, Kyushu islands of Japan and Uruguay experiences the climate.
Cs – the Mediterranean climate is 30°-45° N and S along west margins of the continents. This typical wet winter – dry summer climate results from a seasonal alternation of pressure effectiveness of maritime and marginal water body. The mM air mass effectivity during winters proves the winter concentrated rains in the region. Elsewhere it is invading mP air mass that generate cyclonic storms generating ample rains. In summers, subsiding cT and mT air masses are dominant causing extreme drought like conditions. The major regions of occurrence are central and southern California, coastal zone bordering Mediterranean Sea, SW Australia and SW South Africa.
Cf type of climate is marine west coast type of climate extending between 45°-60° N and S, west margins of the continents. The on share prevailing westerlies, frequent cyclonic storms involving the cool moist mP air mass facilitates the condition. In this humid climate precipitation is copious in all months but with typical winter maxima winter temperatures are very mild compared with inland locations at equivalent latitudes. The regions with the climate are western coast of North America (British Colombia), Western Europe and British Isles, Victoria, Tasmania, New Zealand and Chile.
The ‘D’ type of climate is the temperate climate in the latitudinal stretch between 45°-70° N.
Dw type is the moist continental type. It is the zone of Arctic front seasonal temperature contrasts are strong, while day weather is highly variable. Ample precipitation throughout the year is increased in summer by the invading mT air mass. Cold winters are dominated by cP and cA air masses. Eastern parts of US, Northern Canada, Korea, Japan experiences this climate.
Df type is Taiga/Boreal type. Rainfall is well distributed throughout the year and this latitudinal climate zone is continental climate with long cold winters and short cool summers. This climate occupies the source region of cP air mass. Major areas are Northern Eurasia, Northern Canada.
Precipitation has also been taken to be the basis of one primary class of climate – B type. This dry type of climate has 2 subclasses.
BW type is the desert type extending in the tropical west margins and subtropical continental interiors. Bwh is the source area of cT air mass This subsiding air mass is stable and dry becoming highly heated at surface major regions –Sahara, Arabian Iran, Thar belt, western Australia, Namibia, Atacama and California. BWk is controlled by cT & cP air masses. Aridity is also included by the intermontane characteristics. Central Asia, North western China, Colombia plateau USA, Patagonia Plateau of Artgentina are the regions experiencing this climate.
The BS is the Steppe type of climate.Iit is experienced is the temperate continental interiors This type of climate is also dry mid latitude climate. It precisely occupies rain shadow position with respect to the coastal mountains mP air mass effectivity is strongly blocked and it is thus occupied majorly by cP air mass. Summer rain is caused by sporadic invasions of maritime air mass. Great Plains of USA, European interiors, Pampas of Argentina, Veldt, S. Africa and Downs Australia represents the climate.
Altitude is the ‘H’ type of climate. It is distinctive pattern climate as it represents variations with strong pattern in limited regional extension. The climate of a given highland area corresponds to the climate of the latitude. Thus higher latitude and lower latitude avails most diversity of climatic condition. However this is influenced by the maritime influence as well as the sun bearing slope.
