Genetic climate classification
As genetic climate classification the division of the world in different climates on the location of a particular place is within the global circulation of the atmosphere called. The main criterion for the formation of the climate classes are the global wind circulation systems.
In contrast to the genetic climate classification, the effective climate classification (Troll / Paffen, Köppen / Geiger) is based on the expressions of the climate actually (effectively) found on the earth's surface in the form of temperature values, precipitation values, the existing vegetation (which primarily depends on the given climatic conditions) etc. as arguments for classifying.
Genetic classification according to Flohn and Neef
Hermann Flohn , who developed the most famous genetic climate classification in the 1950s (further developed by Ernst Neef ), distinguishes four global circulation systems:
- The equatorial west wind zone with the intra-tropical convergences ,
- the subtropical dry or passport zone ,
- the extra-tropical west wind zone as well as the
- highly polar east wind zone .
Furthermore, Flohn distinguishes three transitional climates that come about through the seasonal shift in the global circulation systems:
- The marginal tropical climate with summer zenital rain and winter trade winds
- the subtropical winter rain zone with winter westerly winds and summer subtropical high (Mediterranean Sea)
- the subpolar zone with winter polar east wind and summer west wind
The assumption on which the genetic climate classification is based is that, depending on the location of a location within these four global wind systems, the local climate would have to be primarily influenced by these wind systems. So it is assumed that the climate of a place is predominantly generated by the system of global wind circulation (with all its implications). The focus is on the origin (genesis) of the climate from the global circulation of the atmosphere, hence the name “genetic” climate classification.
The climatic beet designed by Flohn in connection with the genetic climate classification is also very well-known and , based on a hypothetical ideal continent , illustrates the earth's climate zones in an idealized way. It is assumed that the land masses do not appear in the shape of the normal continents, but rather form a coherent area that has exactly the extent along each parallel that corresponds to the respective land portion on this parallel. In this way you get a hypothetical continent that looks like an upside down pear or turnip. Hence the name "climatic beet". The climatic zones, which are visibly close to the belts of the global wind systems, are then removed from the climatic beet.
Genetic-dynamic classification according to Terjung and Louie
Another more fundamental type of classification is the genetic-dynamic climate classification, which uses the energy balance ( radiation balance ) as the basis for zoning. This classification was made by WH Terjung and SFS Louie only in 1972, but can be seen as an introduction to the genetic classification, which is based on the general circulation of the atmosphere and the associated wind belt, whereby the genetic-dynamic starts at a deeper level of description . Due to the different balance for different areas of the earth, which are based not only on the net irradiation and radiation, but also on the heat balance ( sensible heat , evaporation heat , heat dissipation from the oceans, etc.), six groups are separated as follows:
- tropical A climates : maximum energy consumption with low fluctuations and high absolute values;
- subtropical B climates : high energy consumption with medium fluctuations;
- C-climates of the middle latitudes continental character: large energy intake with large fluctuations;
- D climates of the middle tropics : medium uptake with very low fluctuations;
- E-climates with a maritime character: medium intake and intake with medium fluctuations, mostly due to the transport of energy with cyclones ;
- Polar G climates : minimal amounts of energy with large fluctuations.
Ernst Neef classified the climate in four constant and three alternating climate zones. Steady means that the climate stays the same over the year, while alternating means a constant change from z. B. wind directions, or pressure areas. Subtle differences, such as the consideration of a maritime influence or the altitude climate, were also advantageous. The problem, however, was that the delimitation between the individual zones is difficult to define.
literature
- H. Flohn: Weather and Climate in Central Europe . 2nd Edition. Research on German regional studies , 78, S. Hirzel Verlag, Stuttgart 1954.
- WH Terjung, S. SF. Louie: Energy input-output climates of the world. In: Archive. Met. Geophys. Biocl. B 20, 1972, pp. 127-66.
