Insolation

insolation [‚in·sō′lā·shən]

(astronomy)

Exposure of an object to the sun.

Solar energy received, often expressed as a rate of energy per unit horizontal surface.

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Insolation 

irradiation of the earth’s surface by solar radiation, direct or total radiation (that is, direct and scattered together). Insolation is usually understood to mean only the amount of radiation received on a horizontal surface. However, the concept of insolation can be broadened to also mean the insolation of surfaces perpendicular to the sun’s rays, vertical surfaces (walls), and inclined surfaces (slopes). The intensity of insolation is expressed by the amount of energy delivered in unit time to a unit irradiated surface (usually insolation is expressed in W/m²).

Insolation depends on the height of the sun above the horizon, the position of the surface irradiated, and the elevation above sea level, as well as on the transparency of the atmosphere and the degree of cloudiness. Therefore, insolation varies considerably both during the course of a day and from season to season. Insolation determines the thermal condition of the earth’s surface and atmosphere and the natural illumination on the earth. Thus, it determines the overall circulation of the atmosphere and the hydrologic cycle on the earth and therefore the earth’s climatic conditions. Biophysical and biochemical processes in plant and animal organisms also depend on insolation.

It is necessary to consider insolation conditions in agriculture and solar therapy. It should also be considered in working out architectural designs, in planning and building towns and cities, and in solving many problems of industry and transportation.

REFERENCE

Kondrat’ev, K. Ia. Akiinometriia. Leningrad, 1965.

S. P. KHROMOV