Showing papers on "Solar constant published in 2019"

Energy Budgets for Terrestrial Extrasolar Planets

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.

Energy Budgets for Terrestrial Extrasolar Planets.

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.

Einstein’s Equation in Nuclear and Solar Energy

Abstract: Starting from the equation of Einstein (E = m·c2), the chapter proposes a simple and fundamental presentation of the fission and fusion principles, together with some of their applications: nuclear reactors and nuclear propulsion vessels and submarines. Fission and fusion are chosen between the multiple forms of energy, as being the most important forms of nuclear energy, directly related with the equation of Einstein. Some characteristics of solar energy, produced from the fusion process inside the Sun, are deducted from the same equation of Einstein: thermal power of solar radiation; specific power of solar radiation; surface temperature of the Sun; solar constant on different planets, etc. The yearly variation of the solar radiation on each planet of the solar system is also presented.

Solar Energy Resource and Its Global Distribution

Abstract: The sun is an extremely powerful energy resource, and the solar energy is an important renewable energy. Solar energy can be used for producing heat and generating electricity. The amount of solar energy incident on earth is enormous, and it is larger than current and predicted energy requirements in the future. In this chapter, the basic concepts and parametrical performance of the sun and its radiation across the space and earth surface including solar irradiance on earth(i.e., diffuse irradiance and direct normal irradiance, the solar constant, extraterrestrial solar spectrum, extraterrestrial solar irradiance, and extraterrestrial solar radiation on a surface), ground-level solar radiation characteristics(atmosphere effects and solar spectrum), solar angles(i.e., the earth–sun angles, hour angle, declination angle, latitude angle, solar altitude, zenith, and azimuth angles), are described. Solar energy global distribution by belt and nation at variable geometrical regions on the globe is also presented.

Prediction of Symmetrical and Asymmetrical of Diurnal Global Solar Irradiance Distribution—New Approach

Abstract: A simple formula to predict the received global solar irradiance q(t), W/m2 for clear days is suggested on pure theoretical basis. It is expressed in terms of the length of the local day time td which is well defined in literatures on meteorological basis. The introduced distribution is also a function of the maximum value of the daily received irradiance qmax. which in turn is expressed in term of the solar constant. This renders the trial to be a closed system. Thus the obtained distribution is not a semi empirical one. Both cases of symmetrical and asymmetrical distributions for q(t) are considered. For its simplicity it can be easily integrated along the length of the day to get the daily totals of solar energy received by unit horizontal area. This is important for practical applications. Comparison between computed according to the present model and published experimental meteorological data in Barcelona (Spain), Hong Kong (China), Jeddah and Makkah (Saudi Arabia) is given as illustrative examples. Better fitting relative to the published trials for the same locations are obtained. The introduced model itself gives good fitting for the intermediate intervals points of the local day time which is the more effective region. The estimated relative error is 12% for Hong Kong, and it is 7% for Barcelona, Jeddah and Makah.

Solar electromagnetic radiation - Space vehicle design criteria /environment/

Abstract: Values for solar constant and solar spectral irradiance based on air and spaceborne observations for use in design of spacecraft, space vehicles, subsystems, and experiments

Solar water outlet device, solar constant-temperature device and solar constant-temperature water outlet system

Abstract: The utility model provides a solar water outlet device, a solar constant-temperature device and a solar constant-temperature water outlet system, and relates to the technical field of solar water heaters. The solar water outlet device comprises a solar water tank and a first water pipe. The other end of the first water pipe is connected with the water mixing valve; the first water pipe is connected with a third water pipe, and a first valve is arranged on the third water pipe; a cold water tank is arranged on the solar water tank, and the cold water tank and the solar water tank are integrallyarranged; the third water pipe is connected with the cold water tank through a fourth water pipe; and a second valve is arranged on the fourth water pipe. The technical problem that in the prior art,a water using point is cold and hot suddenly is solved.

Method and device for calibrating on-orbit radiation of atmospheric absorption channels in remote sensors

Abstract: The invention relates to a method and device for calibrating on-orbit radiation of atmospheric absorption channels in remote sensors. The method comprises the following steps of: respectively obtaining moon irradiance, solar constants, instantaneous field angles and moon observation effective count value cumulative sums of a to-be-calibrated channel in a remote sensor and a reference channel and areference channel calibration coefficient; calculating a moon irradiance ratio, a solar constant ratio, an instantaneous field angle ratio and a moon observation effective count value; and inputtingthe moon irradiance ratio, the solar constant ratio, the instantaneous field angle ratio, the moon observation effective count value and the reference channel calibration coefficient into a to-be-calibrated channel calibration coefficient calculation model so as to calculate a to-be-calibrated channel calibration coefficient. According to the method and device, on-orbit radiation calibration is carried out on atmospheric absorption channels through moon observation data, so that the calibration precision is prevented from being influenced by components of the atmosphere when calibration is carried out on the atmospheric absorption channels by utilizing earth observation data.

Development of Mars surface illumination environment simulation system

Abstract: In order to meet the requirements of Mars rover test, the Mars surface illumination environment simulation system was developed, which is mainly composed of optical subsystem, mechanical and control subsystem. It can simulate the solar elevation angle at a large angle and solar spectrum on Mars surface, etc. It is of great significance for development of Mars rover and the improvement of its ability to perform space exploration missions. After the system was developed, six indexes including irradiance, spectrum, solar elevation angle, illumination area, irradiation uniformity and irradiation stability were evaluated according to the test standards. The irradiance meets the requirement of 0.3 solar constant in the direction of vertical illumination. The spectrum meets the spectral requirements of the landing area; Mars surface illumination environment simulation system can be simulated 75° ~ 90° solar elevation angle, at the same time can be simulated illumination area of more than 10 m × 10 m; The irradiation non-uniformity of this system is ±14% ;Irradiation stability is expressed by irradiation instability, and the irradiation instability of the system is ±4.5% within 2 hours continuously. At present, the Mars surface illumination environment simulation system has participated in the Mars rover test, and the illumination effect has been affirmed by the test department.