Heliogeophysics

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Heliogeophysics

 

a scientific discipline that studies the effect of processes occurring on the sun upon geophysical phenomena. Radiation of the quiet sun (when active processes do not occur on it) consists of electromagnetic radiation, constant in time, in all bands of the spectrum (X-ray, ultraviolet, visible, infrared, and radio) and a weak stream of corpuscles (mainly electrons and protons)—the so-called solar wind. Of the components listed, only the visible radiation and radio-frequency radiation reaches the earth’s surface. The visible radiation carries the bulk of the energy entering the troposphere and hydrosphere and determining the troposphere’s and hydrosphere’s thermal and dynamic regimen. Ultraviolet and X-ray radiations ionize the upper strata of the atmosphere (that is, create the ionosphere) and thus make short-wave radio communications possible over long distances. Corpuscular radiation replenishes the particles in the earth’s radiation belts and the tail of the earth’s magnetosphere, which extends in the direction away from the sun.

When active processes occur on the sun, radiation intensifies in the X-ray, ultraviolet, and radio frequencies of the spectrum and corpuscular streams are ejected (in a narrow solid angle) at speeds of several hundreds of kilometers per second and more. Intensification of short-wave radiation causes the ionospheric strata to become more dense, which leads to weakening or interruption of short-wave radio communications and to improved long-wave radio communication on the lighted side of the earth. Saturating the radiation belts, the corpuscles accelerate in them and penetrate the earth’s atmosphere to the depths of the ionospheric strata in circumpolar regions. This gives rise to anomalous ionization, causing powerful disruptions of radio communications, the aurora borealis and aurora australis, and increased illumination of the night sky (owing to excitation of atoms of the air by the corpuscles). Magnetic storms arise as a result of the motions of the streams of charged particles. In turn, owing to fluctuations in the magnetic field, terrestrial currents and induction currents appear in the wiring of various apparatus, causing disturbances in the functioning of the apparatus. It is possible that corpuscular streams can also change the character of circulations in the terrestrial atmosphere and thus, without changing the total amount of warmth received by the earth, cause it to be redistributed over the earth, that is, cause changes in the weather. The ways that electromagnetic fields related to the solar corpuscles influence various effects in the earth’s biosphere is being studied.

REFERENCES

Mitra, S. K. Verkhniaia atmosfera. Moscow, 1955. (Translated from English.)
Solnechnye korpuskuliarnye potoki i ikh vzaimodeistvie s magnitnym polem Zemli: Sb. st. Moscow, 1962. (Translated from English.)
Pogloshchenie radiovoln v poliarnoi shapke: [Sb. st.] Moscow, 1965. (Translated from English.)
Tverskoi, B. A. Dinamika radiatsionnykh poiasov Zemli. Moscow, 1968.
Dorman, L. I., and L. I. Miroshnichenko. Solnechnye kosmicheskie luchi. Moscow, 1968.

M. N. GNEVYSHEV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.