Köppen Climate Classification Definition
It is already clear that vegetation, temperature, and precipitation are the three main components involved in defining the Köppen Climate Classification.
Before looking in more detail at the different climate regions identified by this system, as well as the role each component play, one needs to obtain a clear and concise definition first of what the Köppen Climate Classification is:
What Is The Köppen Climate Classification?
The Köppen Climate Classification is a widely used meteorological classification system that divides global climate into five primary climate zones based on vegetation. It uses precipitation and temperature, the primary factors determining an area’s vegetation type, to classify a region’s climate.
The close correlation between climate and vegetation, already mentioned in the introduction, forms the basis for this popular classification system.
Late in the 19th century, climatologist and botanist Wladimir Köppen developed a climate classification system based on vegetation. He used the correlation between vegetation and climate in different regions to divide the world’s climate into specific zones.
The resulting Köppen Climate Classification categorizes the global climate into five distinct zones, primarily based on the temperature and precipitation experienced by each one.
Köppen continued to change and refine his classification system, with two of the most important amendments made in 1918 and 1936.
Climatologists continued to make amendments to Köppen’s climate classification. Rudolf Geiger was probably the most influential in making important amendments, and the subsequent Köppen-Geiger Classification System is one of the most widely used today.
Climate Zones Of The World
According to the Köppen Climate Classification, the global climate can be divided into five primary zones. These climate zones are based on regional vegetation and are defined by the temperature and precipitation that are responsible for its formation.
Köppen-Geiger Climate Map depicting the 5 major climate zones and subcategories
The zones are defined by the capital letters A, B, C, D, and E. The climate zones defined by each letter are:
A) Tropical Climates
B) Dry Climates
C) Temperate Climates
D) Continental Climates
E) Polar Climates
Each of the five major climate zones covers a vast region and is divided into smaller categories to describe the more specific climate types within each zone.
The best way to understand each climate type and its characteristics is to look at it within the primary climate zone in which it falls.
A) Tropical Climates
Tropical (also known as equatorial) climates occur in regions situated around the equator and expand to latitudes of 15° to 25° to the north and south. It can be defined by the following characteristics:
- It is the warmest of all the climate zones.
- Regions in this zone have an average monthly temperature of higher than 18° Celsius (64.4° Fahrenheit.)
- Annual precipitation exceeds 1 500 millimeters in this zone.
- High humidity levels and warm temperatures result in frequent, almost daily occurrences of cumulus or larger cumulonimbus cloud formations.
This zone is divided into three subcategories, which are classified according to temperature and dryness.
- 1Af – Tropical Rainforest Climate (no dry season.)
- 2Am – Tropical Monsoon Climate (short dry season)
- 3Aw/As – Tropical Savanna Climate (winter dry season)
B) Dry Climates
Dry (or arid) climates occur in regions situated at latitudes between 20° to 35° north and south of the equator. It can be defined by the following characteristics:
- The main feature of this climate zone is the complete absence or extremely low levels of annual precipitation.
- The very dry atmospheric conditions are the result of the combined evaporation and transpiration levels exceeding the total amount of precipitation.
- Vegetation is sparse or completely absent as a result of the dry climate with very little precipitation.
This climate zone is divided into desert (BW) and semi-arid (BS) regions, according to vegetation type. It is further categorized into hot (h) and cold (k) zones:
- 1BWh – Hot Desert Climate
- 2BWk – Cold Desert Climate
- 3BSh – Hot Semi-Arid Climate
- 4BSk – Cold Semi-Arid Climate
C) Temperate Climates
Temperate (or mesothermal) climates occur in regions situated at latitudes between 30° to 50° north and south of the equator. It can be defined by the following characteristics:
- Regions in this climate zone typically experience warm summers with high levels of humidity and mild winter seasons.
- During the year, the warmest month is at least 10° Celsius (60° Fahrenheit) or higher, while the coldest month is lower than 18° Celsius (64.4° Fahrenheit) but higher than -3° Celsius (26.6° Fahrenheit).
- These climate zones are typically located on the edges of continents, along the eastern and western coastlines.
Temperate climate zones are divided into three main categories according to precipitation: mild temperate dry winters (Cw), mild temperate dry summers (Cs), and mild temperate humid (Cf) climates. All three subcategories are further divided according to temperatures:
- 1Cfa – Humid Subtropical Climate
- 2Cfb – Temperate Oceanic Climate
- 3Cfc – Subpolar Oceanic Climate
- 4Csa – Hot-Summer Mediterranean Climate
- 5Csb – Warm-summer Mediterranean
- 6Csc – Cold-summer Mediterranean Climate
- 7Cwa – Monsoon-Influenced Humid Subtropical Climate
- 8Cwb – Subtropical Highland Climate
- 9Cwc – Cold Subtropical Highland Climate
D) Continental Climates
Continental climates typically occur in regions situated at latitudes between 40° and 75° north and south of the equator. (Although this type of climate is rare in the Southern Hemisphere.) It can be defined by the following characteristics:
- The average temperature of the warmest month is above 10° Celsius (50° Fahrenheit), while the coldest month is below -3° Celsius (26.6° Fahrenheit).
- This climate type is usually found in the interior of continents.
- Regions in this zone experience summers with warm to cool temperatures, while the winters are generally cold.
Continental climate zones are divided into three main categories according to precipitation: continental dry summer (Ds), continental dry winter (Dw), and continental humid (Df) climates. Like temperate climates, they are further divided according to temperature:
- 1Dfa – Hot-Summer Humid Continental Climate
- 2Dfb – Warm-Summer Humid Continental Climate
- 3Dfc – Subarctic Climate
- 4Dfd – Extremely Cold Subarctic Climate
- 5Dsa – Hot Dry-Summer Continental Climate
- 6Dsb – Warm Dry-Summer Continental Climate
- 7Dsc – Subarctic Climate
- 8Dsd – Very Cold Subarctic Climate
- 9Dwa – Monsoon-Influence Hot-Summer Humid Continental Climate
- 10Dwb – Monsoon-Influence Warm-Summer Humid Continental Climate
- 11Dwc – Monsoon-Influence Subarctic Climate
- 12Dwd – Monsoon-Influence Extremely Cold Subarctic Climate
E) Polar Climates
Polar climates are located at latitudes above 70° over the Arctic, Greenland, and Antarctica. It is characterized by its all-year-round cold temperatures and little to no vegetation. The following characteristics define it more precisely:
- The warmest month of the year is below 10° Celsius (50° Fahrenheit).
- Polar climate regions are extremely dry, with annual precipitation of less than 25 cm (10 inches).
Polar climates are divided into two categories according to vegetation:
- 1ET – Tundra
- 2EF – Ice Cap Climate
Tundra Climates consist of very little vegetation (mainly loose shrubs, mosses, and dwarf trees) over a surface where the soil is frozen for several hundred meters. (A condition known as permafrost.) Ice Cap Climates are completely covered by ice or snow.
Conclusion
As clearly illustrated throughout this article, several smaller climate regions exist within each of the five major climate zones. Vegetation, temperature, and precipitation have been the key factors used in determining each subcategory.
Most countries throughout the world experience multiple sub-climates, and many larger regions are influenced by five or more different climate types at any given time. To explain all the climate zones affecting every country/region, though, will fill an encyclopedia.
This post provided a broad and thorough overview of the five climate regions as defined by the Köppen Climate Classification. It highlighted the characteristics of each one, as well as laying out their subcategories and how they were defined.
Never miss out again when another interesting and helpful article is released and stay updated, while also receiving helpful tips & information by simply following this link .Until next time, keep your eye on the weather!
Also Read
Köppen Climate Classification - Defining The Climate Zones Of The World
Köppen Climate Classification - Defining The Climate Zones Of The World
A region’s vegetation primarily results from local, prevailing weather conditions, while the vegetation influences its climate in return. The Köppen Climate Classification system is based on this relationship.
The close correlation between climate and vegetation is evident in every part of the world. (The cold, dry conditions of Antarctica and the moist & humid conditions of the tropical rainforests in South America are just two examples of this powerful interaction.)
The strong connection between the two is also proving to play a key role in categorizing and dividing the global climate into more specific zones. Each climate zone is identified by its unique combination of vegetation, temperature, and precipitation.
These three variables are also determining factors in climate classification. During the late 19th Century, climatologist Wladimir Köppen used vegetation, temperature, and precipitation as the key components in developing the Köppen Climate Classification.
This post describes what the Köppen Climate Classification is and also looks at the different climate zones it defines.
What Is A Fogbow?
As the introduction already alluded to, in the simplest terms, a fogbow appears as a completely desaturated rainbow with a predominantly white appearance.
Before delving deeper into why and how it occurs, a clear and precise definition of a fogbow is needed:
Fogbow Definition
A fogbow is a predominantly white semicircular bow that appears in the presence of fog when water droplets reflect sunlight from within the fog bank. Unlike the luminous spectral colors of a rainbow, a fogbow appears primarily white due to the way microdroplets in fog reflect sunlight.
This summary provides a concise explanation of a fogbow, but to better understand why it occurs and how it differs from its more glamorous cousin, the rainbow, a broader clarification is needed.
Although the name “fogbow” is the most commonly known and widely used name for this phenomenon, a few other terms are also synonymous with this occurrence:
-
- White Rainbow – (Aptly named after its predominantly white appearance.)
- Circle of Ulloa – (Named after General Antonio de Ulloa, who first drew attention to the phenomenon in the 18th century.)
- Ulloa’s Ring – (Another variation of the name used in the previous point.)
- Ghost Rainbow – (Named after the ghostly white appearance of a fogbow.)
A fogbow is a relatively rare sight compared to rainbows and does not occur that often. What makes them even harder to spot is the fact that they can appear almost indistinguishable from the surrounding fog, with only a hint of contrast that makes them visible.
Since a fogbow appears at the antisolar point, the Sun needs to be approximately 20 degrees or less above the horizon for it to be visible as a semicircular ring. Any higher and the phenomenon will theoretically fall below the horizon and disappear from view.
(An antisolar point is a position on the celestial sphere situated directly opposite the Sun from the observer’s point of view.)
The semicircular ring visible above the horizon is only part of a full circle, which can be viewed in its totality if the observer is situated at an elevated position like a mountaintop.
Fogbows are almost as large as rainbows, but the ring (or bow) is much broader due to the amount of diffusion and light scattering caused by the small size of the droplets present in fog.
The following section will detail the process through which a fogbow occurs.
How A Fogbow Occurs
Like a rainbow, a fogbow is observed with your back towards the Sun while looking directly into a bank of fog in front of you.
- The microdroplets in fog diffract (bend) and break up the sunlight into its constituent spectral colors, which results in the familiar color pattern that is so unique to a rainbow.
- However, as the microdroplets in fog are a fraction of the size of raindrops (up to a hundred times smaller), they react and scatter sunlight differently than rainbows.
- The size of the droplets results in the formation of multiple smaller beams of spectral light reflected and scattered in all directions. Many of these smaller beams of light come together, overlap, or merge to display a combined color of white.
- This process explains why a fogbow appears as a predominantly white, ghostly semicircle (sometimes displaying faint spectral colors at the edges, with a hint of red on the outer edge and blue on the inner edge).
Fogbows Are All About Diffraction
The formation of a fogbow is also impossible without the occurrence of a process known as diffraction.
As white light passes through a raindrop (as illustrated by the prism), refraction causes it to be broken up into its constituent spectral colors.
Diffraction is defined as the bending of light as it travels around or through an object. The diffraction of light as it passes through a raindrop is responsible for the breaking up of light into its spectral colors. We view these diffracted colors whenever observing a rainbow or fogbow.
The larger waterdrops in the rain act as a prism and break up (diffract) the sunlight into its constituent spectral colors, which are clearly visible in the resulting luminous rainbow.
Unlike rain, however, the smaller-sized droplets in fog cause less diffraction (bending) of light, which means a smaller separation into constituent spectral colors.
This means the light viewed by the observer appears primarily white (the combination of all spectral colors).
The conditions and specific characteristics of any fogbow may vary from one occurrence to another. However, the process described here, as well as the requirements that need to be in place for the phenomenon to occur, always remains the same.
How To Identify A Fogbow
A fogbow is relatively easy to spot once you know what to look for. It appears as a faint, white semicircular bow in a bank of fog, mostly directly opposite the Sun.
Unlike a rainbow, it has very little, if any, color and can sometimes appear almost indistinguishable from the surrounding fog.
Fogbows are typically seen with the Sun low in the sky, and the observer positioned with their back to the Sun while looking into the fog.
The primary distinguishing feature is its broad, diffuse white arc, often with only a slight hint of color at the edges.
Conclusion
As this post clearly highlighted, the process that is responsible for the formation of a rainbow is identical to the one that creates a fogbow. The only real difference is the size of the droplets in a fog bank.
The size of these microdroplets, though, completely changes the characteristics of a fogbow, displaying a semicircular ring stripped of all its color. It is unique and eye-catching in its own right and can produce a spectacular display under the right conditions.
This article explained what a fogbow is, described its characteristics, and went on to explain its formation in detail.
Until next time, keep your eye on the weather!