Types of world climate and their characteristics
Classification of climate of the world is done to understand how a combination of different climatic elements determine a specific type of climate. There are various systems for classifying the climate globally. However, the Koppen Climate Classification System is the most accepted and widely used system for classifying the world’s climate. This system was developed by Wladimir Koppen in the 1900s and is named after him. In 1900 and afterwards, he continued to revise his system until he passed away in 1940. According to the Koppen Climate Classification System, global climates are often divided into five types as elucidated by Michael Pidwirmy in 2014: Tropical, dry, temperate, cold and polar climates. These divisions of the climate consider a variety of factors such as altitude, atmospheric pressure, wind patterns, latitude and geographical characteristics, for example, mountains and oceans.
Tropical climate
Tropical climate is a non-arid climate in which the mean temperature is above 18°C throughout the year. This type of climate is experienced within 23^ °S and 232°N of the Equator. Tropical climate is characterised by high average temperatures and heavy rainfall. Temperatures in tropical climate are between 21 °C and 32°C, and remain relatively constant throughout the year. Variations in different seasons are dominated by rainfall. Tropical climates cover only two seasons which are the dry season and the wet season. The annual rainfall is around 762 millimetres. This type of climate is found in areas such as central Africa, some parts of South America as well as northern and eastern Australia. Biomes that have tropical climates include rainforests and savannas.
Dry climate
This type of climate experiences very little rainfall and has, therefore, no permanent source of streams. Dry climates are also marked by a wide range of daily temperatures ranging from 32°C to 35°C. A dry climate is divided into semi-arid and arid zones. These zones have three main characteristics: Very low precipitation, high evaporation rates that typically exceed precipitation, and wide temperature swings, that is both daily and seasonally. Dry climates are found mostly between 15° and 35° North and South of the Equator and large continental regions of the mid-latitudes, particularly in the western parts of North America, Australia, southern parts of South America, central and southern Africa and much of middle Asia. Under this type of climate, the primary characteristic is low and unpredictable precipitation. The lowest rainfall is about 150 millimetres occurring in arid or desert areas where the precipitation average is less than 35 millimetres per annum. Moreover, some deserts may go several years with no rainfall. A dry climate often has greater evaporation than precipitation. This results in a climate that lacks ground moisture due to low average rainfall and rapid evaporation. For example, arid regions in the Middle East have an average rainfall of less than 20 millimetres every year whereas the annual evaporation rate is more than 200 millimetres. This is ten times that of precipitation. Extreme evaporation contributes to dry and coarse soils that support little plant life. Semi-arid regions with slightly more precipitation will support some grass and shrubs. This climate has significant variations in seasonal and daily temperatures. This climate is found in some parts of central Tanzania.
Temperature climate
Temperate climate is also known as mesothermal or middle latitude climate. It is found between 30° and 60° North and South of the Equator. Summers tend to be quite warm with little rainfall of about 610 millimetres a year. Winters are moderately wet. Temperate biomes include sub-tropical regions, mediterranean areas and marine or maritime regions. These zones generally have wider temperature ranges of between 17°C and 24°C throughout the year and more distinct seasonal changes than tropical climates, whose variations are often small.
In temperate climates, latitudinal positions, sea or ocean currents. prevailing wind direction, continentality (how large a landmass is), and altitude influence temperature changes.
Cold climate
The cold climate zone lies between 40° and 65° North and South of the Equator and the poles. It includes the Arctic and Antarctic such as parts of Russia and Alaska. Mountain tops have their own cold climate no matter where they arc located. Above the tree line, mountains have a climate similar to that of near the poles. At lower altitudes the climate becomes less cold. Cold climate, also known as .swow, microthermal or continental climates, have a moderate rainfall of about 231 millimetres and high seasonal variations in temperature. These climates tend to be found in central regions of land masses and have an average temperature of above 10°C in their warmest months. In the winter, the coldest month has an average temperature of below -3°C.
Polar climate
Polar climate is found across the continents that border the Arctic Ocean, Greenland and Antarctica. This climate region has year-round cold temperature. It is characterised by lack of a true summer. Parts of the world where a polar climate exists include northern Canada, Siberia, and Antarctica. Weather in these areas is very cold for most of the year and land is covered by thick sheets of ice. Large blocks of permanent ice and tundra are what make these regions distinctive.
During the winter, the regions are entirely dark and extremely cold whereas during the summer, days are long but receive a very small amount of insolation, which makes summers cool as well. The average temperature of the warmest month is less than 10″C. The annual temperature ranges between -40°C and 0°C. The region is dry with less than 25 millimetres of precipitation annually; most precipitation occurs during the summer. The Polar climate regions experience only four months of temperature above the freezing point. They also tend to have months of little daylight.