The climate over a given location is usually the combination of all the climatic elements in a somewhat unique manner determined by the interplay of climatic controls and processes. As a result, there is a wide variety of climate or climatic types prevailing over the earth’s surface. To facilitate the mapping of climate or climatic regions, these numerous climates must be classified using suitable criteria. A climatic region is an area within which climate is broadly uniform from place to place.
We are going to study some of the attempts that have been made in the classification of climate. These are:
i. The Greek system of classification
ii. Koppen’s classification
The Greek system of Classification
Greek philosophers are said to be the first to classify climate. They recognised the relationship between latitude and temperature and devised a system of three zones, namely torrid (within the tropics), frigid (within the polar circle) and temperate (between the two). While the torrid (tropical) climate is very hot, the frigid (polar) climate is very cold and the temperate climate is moderate, not very hot and not very cold.
Koppen’s classification is the most widely used method. It was designed by a man called Wladimir Koppen. Each climate recognised by him is defined according to a fixed value of temperature and precipitation. Five major climatic types were recognised, lettered A to E thus:
a. Tropical rainy climate: The temperature of tiff coldest month is above 18 degrees. The annual rainfall is greater than the annual evapotranspiration.
b. Dry climate: The mean annual potential evapotranspiration exceeds the mean annual precipitation.
c. Warm temperate or mesothermal climate: The coldest month has a mean temperature below 3 degree Celsius and 18 degree Celsius while the warmest has a mean more than 10 degrees Celsius.
d. Cool snow-forest or microthermal climate: The coldest month has a mean temperature below 3 degrees Celsius and warmest more than 10 degrees Celsius.
e. Polarorice climate: The warmest month has a mean temperature less than 10 degrees Celsius.