Solar constant

About: Solar constant is a research topic. Over the lifetime, 967 publications have been published within this topic receiving 29647 citations.

The Solar Constant and Terrestrial Magnetism

Abstract: DR. CHREE has obligingly sent me a copy of his paper entitled “The Relationship between the Solar Constant and Terrestrial Magnetism” (Proc. Roy. Soc. A 109, 1925). He finds no indication in the solar constant data of 1918–1924 of a repetition of departures after a solar rotation period. This finding is quite in accord with ours. We have, indeed, noted the solar rotation period very plainly in some of the data, but only for a few months at a time, as in the year 1915. (See C. G. Abbot, “On Periodicity in Solar Variation”, Smithsonian Miscellaneous Collections, vol. 69, No. 6, 1918.)

Genesis of sun photometry

Abstract: In early studies of the sun’s spectrum it was found that the atmosphere diminishes the intensity of solar radiation. In general the effect is larger in the blue or violet than at longer wavelengths. This is why a scene viewed through a red filter, such as red cellophane, appears to be so “clear”. It was further discovered in the nineteenth century that the diminishing effect of the atmosphere can actually be more complicated than a smooth blue-to-red gradient and that certain wavelengths of sunlight are strongly absorbed by individual trace gases in specific wavelength bands and, moreover, to complicate things even further the diminution or “turbidity” was found to vary from one day to another. Assessing this “diminution” nuisance became especially important in quantifying incoming solar radiation reaching the earth. The investigation of solar radiation reaching the earth became a subject of great interest because it was suspected that the sun may undergoes changes in its luminosity that would modulate climate and weather and the growing of crops.

Variation of the solar constant connected with the coronal activity

Abstract: A strong correlation was found between the dips in the total solar irradiance and the peaks in the active sunspot areas as well as in the 260 MHz coronal radio flux. This connection might indicate that Alfven-waves, generated during the interaction of the magnetic fields of the active sunspot groups with the convection, are able to transport away part of the missing energy in the solar constant decreases. These waves can heat the solar corona above the sunspot groups. Another part of the missing energy could be re-radiated later, for example during the decay of the active regions.

Change in the solar constant between 1968 and 1978

Abstract: Solar irradiance measurements made from a balloon on January 27, 1978 and February 10, 1980 show a change of 0.4% over similar measurements made in 1968. This change is greater than the uncertainty of the measurement and is felt to be the result of a change in the solar constant.