Short essay on Middle-Latitude Steppes Climate (BSk)

Middle-latitude steppes, too, like the low-latitude steppes are found in the transition zone between the deserts and the humid climates. These steppes are situated in the interior parts of the continents in the temperate zone.

These regions, because of their location, are deprived of the marine influence. Extreme continentally is the key-note of the climatic conditions of the middle- latitude or continental steppe climate.

Location:

Because of the wide expanse of North America and Eurasia in middle latitudes, the BSk climates are found in extensive regions of these two great continents.

In North America the middle-latitude steppe climate extends from Alberta to Colorado east of the Rockey Mountains.

The steppe regions also occupy the larger mountain basins and the Columbia Plateau region between the Northern Rockies and the Cascades Mountains of Washington and Oregon. In Saskatchewan and Alberta this type of climate is found as far north as 54° N.

Temperature:

Unlike their counterparts in the low-latitudes, the middle-latitude steppes are characterized by their cold winters. Such a season of severe cold is absent in the low latitudes.

These steppes by virtue of their interior locations have warm summers and cold winters resulting in large annual ranges. Besides, because of a wide latitudinal spread ranging from 15° to 20° both in North America as well as Asia, there is great variation in the average temperatures of the steppe regions on their pole-ward and equator-ward margins.

Temperatures are too severe for any given latitude. Tashkent and Semipalatinsk in U.S.S.R. have winter averages of 0°C and -12°C respectively. Temperature at Laramie, Wyoming ranges from -6.7°C in January to 16.7°C in July.

During the high sun period, average temperature for the warmest month may exceed 27°C, whereas in January the average may drop to sub-freezing temperatures.

Diurnal ranges of temperature are also bound to be large because of dry air and other factors discussed in the low-latitude steppes and deserts.

In the Southern Hemisphere, the middle-latitude steppes do not exhibit such seasonal contrasts because of the limited land masses in the temperate zone. But daily ranges of temperature are quite as large there too.

Precipitation:

The amount of precipitation received annually in the steppe regions is greater than that in deserts. The middle-latitude steppe regions have an annual average precipitation between 20 to 50 cm. humid years, however, may be followed by several drought years.

In addition, years with below- normal precipitation are common. Like the low-latitude steppe climate, the total amount of precipitation falling in these regions is, of course, less than the potential evaporation.

The amount of precipitation may vary greatly from one year to another. The seasonal distribution of precipitation, in the steppe climate varies according to its location with respect to other climatic regions.

Some parts of the steppe regions may receive summer precipitation, while other parts may get winter precipitation from the cyclones. Variability and undependability are the chief characteristics of precipitation in the middle-latitude steppe climate.

The North American and Asian middle-latitude steppe regions are open to onslaughts of both tropical and polar air masses. Therefore non-periodic weather changes in these regions are more common.

During winter, most of the steppe regions are under the influence of strong anticyclones so that weather is dry and calm. On occasions, the extra-tropical cyclones visiting these regions yield snowfall, and strong winds follow.

Such high-velocity and snow-laden winds on the North American Plains are called blizzard. In summer, on the contrary, dust or sand-laden scorching winds are the rule.

Natural vegetation and animals:

Middle-latitude semi-arid regions, because of meager precipitation, support short-grasses and shrubs. The short-grass prairie of North America offers the best example of the middle-latitude steppe vegetation.

In South Africa, the short-grass region is known as veldt. Presently these steppe grasslands are the great sheep and cattle ranches.

The steppes of central Asia have been famous for their nomadic population (Kirghiz) moving from one place to another with their sheep and goats in search of fresh pastures. Besides, large herds of grazing animals as well as carnivores are found on these grasslands.