Social Sciences, asked by rajneshbasliyal2020, 8 months ago

there is extreme heat in desert​

Answers

Answered by sshi
2

Deserts are hot primarily because of a lack of water. When the sun shines on the ground, all of the absorbed sunlight goes into raising the ground's temperature. If there was moisture in the soil, much of this heat would go into evaporation of some of the water, which requires heat to accomplish, and thus keeping the soil cooler that it would otherwise be. This cooling is from the "latent" heat of evaporation that is required to change liquid water into water vapor, and is the same reason why water evaporating from your skin feels cold.

Associated with the lack of water is a lack of vegetation, which would also cause water to evaporate as part of photosynthesis -- a process called evapotranspiration.

The common perception that deserts are hot because of the bright sand is incorrect. Since vegetation is darker than most desert soils, if a desert could have vegetation that didn't need water to live, the desert would actually be hotter since it would absorb more sunlight. Instead, the vegetation causes water to evaporate (and uses some of the sunlight for other plant growth process). Similarly, if deserts were covered by dark soil rather than light soil or sand, they would also be hotter.Interesting facts:DESERTS ARE COLD AT NIGHT:Because of the lack of water in the ground, and little water vapor in the air, most deserts can get quite cool at night. This is because (1) dry ground does not retain as much heat as moist ground, and (2) water vapor is the most important greenhouse gas, so dry air allows the surface to cool rapidly at night through loss of infrared radiation to outer space.

In fact, it has been calculated that the Sahara Desert actually loses more infrared radiation than it gains solar radiation from the sun. This net loss of radiant energy is balanced by the sinking air over the desert, which warms as it is compressed. The air over the desert is, in turn, being forced to sink by rising within rain systems hundreds or thousands of miles away. Thus, in some sense, rain can be considered the cause of deserts(!).(page last updated 12/13/2019)

Answered by SAIRAMSRINIVASAN9098
0

Answer:

A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to the processes of denudation. About one-third of the land surface of the world is arid or semi-arid.

Deserts are formed by weathering processes as large variations in temperature between day and night put strains on the rocks, which consequently break in pieces. Although rain seldom occurs in deserts, there are occasional downpours that can result in flash floods. Rain falling on hot rocks can cause them to shatter, and the resulting fragments and rubble strewn over the desert floor are further eroded by the wind. This picks up particles of sand and dust and wafts them aloft in sand or dust storms. Wind-blown sand grains striking any solid object in their path can abrade the surface. Rocks are smoothed down, and the wind sorts sand into uniform deposits. The grains end up as level sheets of sand or are piled high in billowing sand dunes. Other deserts are flat, stony plains where all the fine material has been blown away and the surface consists of a mosaic of smooth stones. These areas are known as desert pavements, and little further erosion takes place. Other desert features include rock outcrops, exposed bedrock and clays once deposited by flowing water. Temporary lakes may form and salt pans may be left when waters evaporate. There may be underground sources of water, in the form of springs and seepages from aquifers. Where these are found, oases can occur.

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