Koeppen’S Climate Classification

Introduction

The Koppen climate classification scheme is a commonly used vegetation-based climatic classification system developed by Wladimir Koppen, a German botanist and climatologist. The Koppen climate classification system is an endeavour to devise a formula for delineating climatic borders in accordance with vegetation zones or biomes across the world.

The Köppen climate classification categorizes climates into five classes, with each class subdivided depending on precipitation patterns and temperature trends. The five major classes are A (tropical), B (dry), C (temperate), D (continental), and E. (polar). Each class and subclass is denoted by a letter. A main class is designated to each climate (the first letter). Except for those in the E group, all climates are allocated a seasonal precipitation subgroup (the second letter).

Moist Tropical Climates

Tropical moist conditions are found between the latitudes of 15 and 25 degrees north and south of the equator. The fact that weather conditions in these zones are over 18 degrees Celsius all year distinguishes this climatic zone. In this climate zone, yearly precipitation is frequently more than 1,500 mm.

Within this broad climatic zone, there are three minor climatic classifications that are categorized subject to seasonal variations in precipitation. These climatic regions are frequently distinguished by naturally thick tropical forests.

The first kind is Af, which is also known as tropical wet climate. This category has a tropical climate with rainfall all year. Temperature changes in these areas are fewer than 3 degrees Celsius every month.

Cumulonimbus and cumulus clouds occur early in the afternoons each day in these places due to unusually high moisture and surface temperatures, which results in a large amount of rain.

The second kind of climate is tropical monsoon climate, abbreviated as Am. The yearly precipitation in these places is roughly the same as that in Af, however the majority of the precipitation occurs during the 7 to 9 hottest months of the year. During the remainder of the year, these areas receive less rainfall.

Aw, or the tropical wet and dry climate, or the savannah climatic condition, is the third subdivision. During the wintertime, these climatic zones have a prolonged dry spell. Rainfall during the wet season is often less than 1,000 mm and happens primarily during summer.

 Dry Climates

Temperature is not as important in these climatic zones as precipitation, or the absence of it thereof. Evaporation and transpiration exceed total precipitation in these climatic zones. These climatic zones range in latitude from 20 to 35 degrees north and south of the equator and are found in huge continental regions in the mid-latitudes or are surrounded by mountainous regions. This climatic zone is divided into four large subdivisions. The first is BW, or dry arid climate, often known as the genuine desert climate, which encompasses around 12% of the Earth’s total surface area. This climatic zone has environments for xerophytic vegetation. The letters h and k are affixed after BW to indicate whether the dry arid zone is in the subtropics or the mid-latitudes, respectively.

The second kind of climate is BS, which stands for dry semi-arid climate, commonly known as steppe climate. This results in a grassland climate, which covers around 14% of the Earth’s surface. The dry semi-arid climate, or BS, gets more precipitation than the dry arid climate, or BW, owing mostly to mid-latitude cyclones or the intertropical convergence zone. The letters h and k, like BW zones, are suffixed to designate the position of the climatic zone in the subtropics or the mid-latitudes, respectively.

 Moist Subtropical Mid-latitude Climate zones

Summers in this climatic zone are often hot and humid, while winters are moderate. These climatic zones reach 30 to 50 degrees latitude north and south of the equator and are found mostly in the eastern and western extremities of most continents. The first is the humid subtropical climate, or Cfa, which has hot and humid summers with frequent thunderstorms. Winters are moderate, and precipitation occurs as a result of mid-latitude cyclones, like in the southeastern United States. The second kind of climate is the Cfb marine climate, which is often found on the western shores of continents. The climate in this area is mostly humid, with a hot and dry summer. Winters are warm, however they are accompanied by significant precipitation from mid-latitude cyclones. The third climatic zone is the Mediterranean climatic zone, or Cs, where rain appears mostly during the mild winters owing to mid-latitude storms.

Climates of Moist Continental Mid-latitudes

Summers in wet continental mid-latitude regions are mild and can be chilly, while winters are freezing. The moist continental mid-latitude climates are often found pole-wards of moist subtropical mid-latitude climates, or C climates. Temperatures in the hottest months typically exceed 10 degrees Celsius, while temperatures in the coldest months can fall below minus 3 degrees Celsius. Winters in these areas may be very cold, with strong winds and snowstorms originating in the Continental Polar and Arctic air masses. This kind of Koppen climatic classification has three subdivisions: Dw – with dry winters, Ds – with dry summers, and Df – with precipitation all year.

Polar Climates 

Temperatures in polar areas are low all year, with the hottest month having temperatures of less than 10 degrees Celsius. Polar climates may be found along the northern coasts of Asia, Europe, and North America, as well as on Greenland and Antarctica. There are two types of polar climates. The first is ET, or Polar Tundra, where soil is as permanently frozen as permafrost and extends hundreds of metres into the ground. The majority of the vegetation found here is in the form of dwarf trees, woody shrubs, lichens, and mosses. The second kind is EF, or Polar Ice Caps, that have a perpetually coated surface with ice or snow.

Conclusion

This study employed a worldwide temperature and precipitation observation dataset to uncover climatic variations and changes from 1901 to 2010, revealing the potential of the Köppen classification in capturing not just climate change, but also climate variability at different temporal scales. The most noteworthy shift from 1901 to 2010 is a marked areal rise in the dry climate (B) followed with a considerable areal drop in the polar climate (E) during the 1980s. There are also areas of spatially stable climatic zones for inter annual and inter decadal changes, which have practical and theoretical ramifications.