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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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Journal ArticleDOI
B. W. Forgan1
TL;DR: The basic requirement for any type of measurement in which comparisons are made in a scale, relative or absolute, is that the value derived lies within the error bounds of all the values used in the analysis.
Abstract: The basic requirement for any type of measurement in which comparisons are made in a scale, relative or absolute. The values used by the Committee on Solar Electromagnetic Radiation to derive the solar constant were in different radiometric scales. Assuming that only difference in radiometric references produced the wide scatter of individual values, an attempt was made to convert all values to one radiometric reference. A radiometric scale based on electrical power equivalence was used as the reference. The resulting value was 137.5 mW · cm−2, as compared to the CSER derived value of 135.3 mW · cm−2. This revised value lies within the error bounds of all the values used in the analysis. The revised estimate was then compared to values derived from more recent experiments. There appears to be a discrepancy between values derived in and out of the atmosphere.

8 citations

Journal ArticleDOI
TL;DR: In this paper, a solar irradiance measurement made from a balloon on January 27, 1978, indicates a change of +0.4% over similar measurements made in 1968, this change is greater than the experimental uncertainty of the measurement and is felt to be the result of change in the solar constant.
Abstract: Solar irradiance measurement made from a balloon on January 27, 1978, indicates a change of +0.4% over similar measurements made in 1968. This change is greater than the experimental uncertainty of the measurement and is felt to be the result of change in the solar constant.

8 citations

Proceedings ArticleDOI
03 Jun 1991
TL;DR: In this paper, the spectral atmospheric optical properties required by the twostream equations: the single-scattering albedo, scattering asymmetry parameter, and optical depth are used to obtain the direct and diffise spectral irradiance over a flat surface.
Abstract: In this research I show how LOWl'RAN7 can be used with a twostream atmospheric radiative transfer algorithm to model the topographic distribution of solar radiation under various meteorological conditions. LOWTRAN7 is modified to give the spectral atmospheric optical properties required by the twostream equations: the single-scattering albedo, scattering asymmetry parameter, and optical depth. The twostream equations are then used l,o obtain the direct and diffise spectral irradiance over a flat surface. There irradiances are spectrally integratled through the wavelength range 0.3 - 3.0 pm and finally adjusted for the effects of topography. The method is applied to a basin and range desert landscape under calm ancl windy conditions and maps of daily integrated radiation are presented. For applications at specific field sites, LOWTRAN7 can also be used to estimate twostream parameters that yield the same flux as measured by scattered pyranometers. The method is demonstrated using pyranometer data collected over the Konza Prairie, Kansas, during the First ISLSCP Field Experiment (FIFE). keywords: solar radiation, topography, LOWTRANII.

8 citations

Journal ArticleDOI
06 Mar 2021-Agronomy
TL;DR: In this paper, the authors used Simulink-MATLAB blocks to facilitate its application, using the day of the year, the time of day, and the hourly horizontal global solar irradiation as input variables.
Abstract: Agrometeorological stations have horizontal solar irradiation data available, but the design and simulation of photovoltaic (PV) systems require data about the solar panel (inclined and/or oriented). Greenhouses for agricultural production, outside the large protected production areas, are usually off-grid; thus, the solar irradiation variable on the panel plane is critical for an optimal PV design. Modeling of solar radiation components (beam, diffuse, and ground-reflected) is carried out by calculating the extraterrestrial solar radiation, solar height, angle of incidence, and diffuse solar radiation. In this study, the modeling was done using Simulink-MATLAB blocks to facilitate its application, using the day of the year, the time of day, and the hourly horizontal global solar irradiation as input variables. The rest of the parameters (i.e., inclination, orientation, solar constant, albedo, latitude, and longitude) were fixed in each block. The results obtained using anisotropic models of diffuse solar irradiation of the sky in the region of Castile and Leon (Spain) showed improvements over the results obtained with isotropic models. This work enables the precise estimation of solar irradiation on a solar panel flexibly, for particular places, and with the best models for each of the components of solar radiation.

8 citations

Journal ArticleDOI
TL;DR: In this article, the authors quantified the flow of energy on aqua planets orbiting M-, G-, and F-dwarf stars, using a 3D Global Climate Model with a static ocean.
Abstract: The pathways through which incoming energy is distributed between the surface and atmosphere has been analyzed for the Earth. However, the effect of the spectral energy distribution of a host star on the energy budget of an orbiting planet may be significant given the wavelength-dependent absorption properties of atmospheric CO2 and water vapor, and surface ice and snow. We have quantified the flow of energy on aqua planets orbiting M-, G-, and F-dwarf stars, using a 3D Global Climate Model with a static ocean. The atmosphere and surface of an M-dwarf planet receiving an instellation equal to 88% of the modern solar constant at the top of the atmosphere absorb 12% more incoming stellar radiation than those of a G-dwarf planet receiving 100% of the modern solar constant, and 17% more radiation than a F-dwarf planet receiving 108% of the modern solar constant, resulting in climates similar to modern-day Earth on all three planets, assuming a 24-hr rotation period and fixed CO2. At 100% instellation, a synchronously-rotating M-dwarf planet exhibits smaller flux absorption in the atmosphere and on the surface of the dayside, and a dayside mean surface temperature that is 37 K colder than its rapidly-rotating counterpart. Energy budget diagrams are included to illustrate the variations in global energy budgets as a function of host star spectral class, and can contribute to habitability assessments of planets as they are discovered.

8 citations


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