He Subtropical climate Is characterized by summers ranging from warm to hot and from mild winters to cold, with rare frosts.
Most subtropical climates are divided into two basic types: subtropical humid and dry summer or Mediterranean.
Areas of the world with subtropical climate
- Humid subtropical , Where rain usually concentrates in the hottest months (Brisbane, Australia, or Jacksonville in Florida).
- Dry summer , Or Mediterranean, where seasonal precipitation is concentrated in colder months (eg Naples in Italy or Los Angeles in California).
Subtropical climates also occur at high elevations within the tropics, such as the southern tip of the Mexican plateau in Vietnam and Taiwan. From this classification six climatic subclassifications are given to facilitate the identification of the different regimes of temperature and precipitation.
Much of the world's deserts are found within subtropical zones. In the subtropical savannas, summer is considered the wet season and is when the greatest amount of annual precipitation falls. Within the Mediterranean climatic regimes, the wet season is winter.
Areas that border the warm oceans receive intense local rains because of tropical cyclones that encourage them. The plants grown in these areas are palm trees, citrus, mango, lychee and avocado, among others.
Background of the climatic classification
The earliest known climatic classifications were those of the classical Greek period, whose schemes generally divided the Earth into latitudinal zones based on the significant parallels of 0 °, 23.5 ° and 66.5 ° latitude (ie, the Equator, the Tropics of Cancer and Capricorn, and Arctic and Antarctic circles, respectively), taking into account the length of the day.
The modern climatic classification has its origins in the middle of the nineteenth century, with the first published maps of temperature and rainfall on the surface of the Earth, which allowed the development of methods of climatic clustering that used both variables simultaneously.
Maps of climatic zones. Via Encyclopædia Britannica, Inc.
The angle that forms between the line of the Equator and a meridian, is called latitude: south latitude for the southern hemisphere and north latitude for the northern hemisphere. The subtropical climate is located in areas in a range of latitude between 30/40 ° and 45 °.
Data collection and analysis of these areas show that the hot season is longer, while the cold season is more benign and rainy. Latitude has a direct influence on the determination of the climates of the different zones. Between Ecuador and the tropics, the climate is warm, and at a greater distance from the equator and closer to the north and south poles, it becomes colder.
Representation of Latitude
Subtropical climates: traditional classification
Classification of Köppen
In 1920, Wladimir Peter Köppen Developed a classification system for climates based only on precipitation and temperatures. The Köppen classification system is still discussed and taught in academic settings.
Each climate has a two- or three-letter code. The letter C is used to identify areas of subtropical climate - temperate climate - whose average temperature is 22 ° C in warm months.
Köppen also identifies subtropical regions of constant humidity. Others, with a dry season, defined as areas of typical Mediterranean climate: very dry summers that determine the flora and fauna of the region.
Classification of Strahler
Strahler (1969) classifies the subtropical climates in:
- Humid subtropical or Chinese climate
- Dry subtropical or Mediterranean climate
Subtropical climate classification
A) Humid subtropical climate
The humid subtropical climate, the main climatic type of the Köppen classification, is characterized by relatively high temperatures and uniformly distributed rainfall throughout the year.
This type of climate is found on the eastern sides of the continents between 20 ° and 35 ° N and latitude S. Although the climate is composed of two subtypes (Cfa and Cwa), the subtype Cfa predominates (see point 2.1.).
In summer, these regions are largely influenced by the flow of moist and maritime air from the western side from the subtropical anticyclonic cells in low latitudinal ocean waters.
Temperatures are high; In the warmest months, the average is generally 27 ° C (81 ° F), with average daily highs ranging from 30 ° C to 38 ° C (86 ° F to 100 ° F) and warm, suffocating nights.
Summers are generally somewhat wetter than winters, with heavy rains coming from the convection activity of storms (strong upward and downward movements that produce a series of characteristic effects such as heavy rains and surface winds and intense electrical discharges) .
In some regions, tropical cyclones also produce more rainfall in the warm season. The coldest month is usually mild (5-12 ° C (41-54 ° F), although there may be frosts, and winter precipitation comes mainly from the front cyclones originating from the polar front.
In North America, in spring and early summer, when the front begins its return northward, tornadoes associated with frontal storms are generated along the zone of interaction between tropical and polar air.
In eastern and southern Asia, monsoon influence results in a modified humid subtropical climate (Cwa) with a dry winter clearly defined by the action of the Siberian anticyclone, and the polar front and cyclones moving around the region.
This phenomenon is concentrated in the tropical climates of the monsoon (Am) and tropical humid-dry (Aw) and exhibit an annual temperature range somewhat higher than the Cfa types.
The winters are sunny and quite cold. Annual precipitation sums an average of 100 cm (39 inches), but ranges from 75 to over 200 cm (30 to 79 inches).
B) Mediterranean climate
Main climatic type of the classification of Köppen, is characterized by warm and dry summers and cold and humid winters. It is located between the 30 ° and 45 ° of north latitude and south of the Ecuador and to the western sides of the continents.
In the Köppen-Geiger-Pohl system, it is divided into the subtypes Csa and Csb. The expansion and expansion of the subtropical anticyclonic centers above the oceans, in summer, bring the air to the region, with clear skies and high temperatures.
When in winter, the anticyclone moves towards the Ecuador, frontal cyclones appear that generate rains. Annual temperature ranges are generally broader than those found in the west coast coastal climates, since the areas located on the western sides of the continents are not well positioned to receive the colder polar air, which expands over the Humid subtropical centers, with total rainfall between 35 and 90 cm (14 to 35 inches).
In the interior regions adjacent to the semiarid steppe the precipitations are smaller.
Some coastal locations (such as southern California, western United States) have relatively cold summers and frequent fog due to the prevalence of cold coastal currents.
Only in Europe, where the latitude for this type of climate corresponds to the ocean basin of the Mediterranean Sea (hence the name of the climate), these climatic conditions extend to the east, well beyond the coast.
Subtropical desert climate
The tropical and subtropical desert climate, which according to the Köppen classification predominates in all months of the year due to the subtropical anticyclone with its descending air, high investments and clear skies.
Such an atmospheric condition inhibits rainfall. Most of the tropical climates are present in the Panther (BW) deserts, located between 15 ° and 30 ° latitude, at the end of the Hadley cell circulation.
The Köppen-Geiger-Pohl system establishes two subtypes, the tropical desert (BWh) and the subtropical desert (BWk).
Subtropical steppe climate
Climate of tropical and subtropical steppe (classification of Köppen), occurs mainly in the periphery of the real deserts, in regions of semiarid steppe of low latitude. Such regions are designated by the abbreviation BSh in the Köppen-Geiger-Pohl system.
It is transitional to the humid-dry tropical climate towards the equator, showing maximum rainfall in summer, associated with the intertropical convergence zone and a low annual temperature range, and the Mediterranean climate towards the poles, with wetter and colder winters .
Annual precipitation totals are higher than in tropical and subtropical desert climates (38-63 cm, 15-25 inches). The annual variations in quantity are not as extreme as in genuine deserts, yet they are considerable.
- Arnfield, J. Climate classification. Retrieved on 01/28/2017 on britannica.com.
- Classification of Köppen adapted for this article. Recovered on 01/28/2017 at meteorologyclimate.com.
- Arnfield, J. Climate classification. Retrieved on 01/28/2017 on britannica.com.
- Humid subtropical climate. The Editors of Encyclopædia Britannica. Retrieved on 01/28/2017 on britannica.com.
- Mediterranean climate. The Editors of Encyclopædia Britannica. Retrieved on 01/28/2017 on britannica.com.