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Solar constant

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


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Book ChapterDOI
01 Jan 1995
TL;DR: The sun is the universal source of energy in the biosphere as discussed by the authors, and the energy emission of solar radiation corresponds to the continuous emission spectrum of a black body at 5800 K. Because of scattering and selective absorption of quanta in the earth's atmosphere, the spectrum of the sun is modified (Fig. 12.1) so that the energy flux is reduced from 1.4 (the solar constant) to ≤ 0.9 kW · m−2 (sea level).
Abstract: The sun is the universal source of energy in the biosphere. During the nuclear-fusion processes occurring in the sun, matter is changed into energy (e.g. 4 protons → helium nucleus + 2 positrons + 4.5 · 10−12 J) which is emitted in the form of electromagnetic radiation (h v) into space. The energy emission of solar radiation corresponds, as a first approximation, to the continuous emission spectrum of a black body at 5800 K. Because of scattering and selective absorption of quanta in the earth’s atmosphere the spectrum of the sun is modified (Fig. 12.1) so that the energy flux is reduced from 1.4 (the solar constant) to ≤0.9 kW · m−2 (sea level). Approximately half this energy is within the 300–800 nm spectral band (“optical window” of the atmosphere; Fig. 12.1) which is in the centre of the photochemically active radiation band (approximately 100–1000 nm).

6 citations

Journal ArticleDOI
01 Mar 1983-Nature
TL;DR: In this paper, a change in the strength of photospheric lines during the ascending part of the current solar cycle is predicted using stellar model-atmosphere techniques, and its magnitude is predicted by a 0.2% decrease of the irradiance in the blue, and an increase of the same order in the red and near IR.
Abstract: Precise monitoring of the solar absorption-line spectrum in the period 1976–80 has revealed systematic changes of the strength of photospheric lines during the ascending part of the current solar cycle1. The most likely cause is a slight cooling of the lower photosphere and a concomitant heating of higher layers. The total energy radiated into space thereby remains unchanged, in accordance with high-precision radiometry2 covering the same period. Nevertheless, a flattening of the photospheric temperature gradient will be accompanied by a redistribution of energy in the solar spectrum. Its magnitude is predicted here using stellar model-atmosphere techniques. This ‘change of colour’ is characterized by a 0.2% decrease of the irradiance in the blue, and an increase of the same order in the red and near IR. In this way solar activity may modulate terrestrial climate even in the absence of perceptible changes of the solar constant.

6 citations

Journal ArticleDOI
TL;DR: In this article, a general design procedure is presented which allows a rapid graphical solution of the performance of the generator for a matched load condition, and its performance is evaluated for solar concentrations of 1 to 2 times the solar constant, segmenting of the thermoelements with compatible Bi2Te3 cooling material, increase of the area of the radiator plate over that of the collector plate, and for a satellite probe to pass by Venus.
Abstract: A general design procedure is presented which allows a rapid graphical solution of the performance of the generator for a matched load condition. Furthermore, its performance is evaluated for solar concentrations of 1 to 2 times the solar constant, segmenting of the thermoelements with compatible Bi2Te3 cooling material, increase of the area of the radiator plate over that of the collector plate, and for a satellite probe to pass by Venus.

6 citations

Proceedings Article
01 Oct 2008
TL;DR: In this article, a curved surface renewable solar cell is applied to provide a near space airshippsilas energy system the power to drive the high altitude electromotor and propeller in a long term.
Abstract: Curved surface renewable solar cell is applied to provide a near space airshippsilas energy system the power to drive the high altitude electromotor and propeller in a long term. The solar flux incident on the solar cell is calculated through integral transform and some revised correlations from tilted surface solar radiation flux calculations. In view of the solar radiation flux and the wind speed fluctuation and randomicity, wavelet analysis and genetic algorithm aided neural networks are combined to make the solar radiation flux predictable and real-time with higher precision than solar constant radiation spatial interpolation.

6 citations

Journal ArticleDOI
TL;DR: In this article, the authors report the results of unique observations of the solar eclipse of March 29, 2006 over a wide radio-wavelength range from 1 to 50 cm made with the large RATAN-600 stationary radio telescope during the maximum eclipse phase performed using the method of the source transit across the fixed beam pattern.
Abstract: We report the results of unique observations of the solar eclipse of March 29, 2006 over a wide radio-wavelength range from 1 to 50 cm made with the large RATAN-600 stationary radio telescope during the maximum eclipse phase performed using the method of the source transit across the fixed beam pattern. The multifunctional opportunities of the radio telescope allowed observations to be performed simultaneously in a part of the Northern sector of RATAN-600 and in the Southern-sector plus periscope mode using all the available receiving equipment at the corresponding secondary mirrors. At the time of maximum eclipse phase a narrow 1—3-arcsec wide crescent-shaped band near the North Solar Pole remained visible out of the entire solar disk covered by the Moon. We achieved high flux sensitivity, which allowed us to discover a large polar radio source located above the North Solar Pole and obtain detailed data on its radiation and spatial structure. Moreover, we detected optically thin radiation of the solar corona at the brightness-temperature level of several K or several tens of K. We find this radiation to extend beyond the solar limb out to the heliocentric distances of one solar radius. These data are unique in that they are not contaminated by scattered radiation of the solar radio disk, which usually shows up in ordinary observations. We are the first to obtain a detailed spectrum of the radiation of a high-latitude prominence at many wavelengths with a 1% frequency resolution in the microwave range, which allowed us to estimate its magnetic field at a number of levels in the lower corona.

6 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20238
202215
20219
20202
201911
201810