Solar constant

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

Solar Cycle Variation of the Microwave Spectrum and Total Irradiance

Abstract: We have extended the proxy relationship between irradiance and microwaves by using the daily solar fluxes from Toyokawa Observatory at 1000, 2000, 3750 and 9400 MHz in addition to the Ottawa 2800 MHz flux for the years 1980–1989 It turns out that the flux at 1000 MHz is better correlated with irradiance than the flux at higher frequencies-an unexpected result We have also found that the spectrum of the flux shows shape changes that are related to the number and type of active regions Because of this the five-frequency spectral measurements of microwave flux allow one to separate the sunspot and coronal features, providing an improved proxy of solar variability

Variations in the Solar Constant Caused by Changes in the Active Features on the Sun

Abstract: The solar constant is calculated as a function of time using known contrast values for active features on the Sun. The photospheric effective temperature is assumed to be constant in this model and the change in radiant output is assumed to be caused solely by active features on the Sun which have different effective temperatures than the surrounding photosphere. The theoretical annual mean solar constant varies by no more than 0.102 mW cm−2 or 0.075% of its value. For the more active Sun the solar constant is lower. If the energy flux from the deep interior of the Sun is constant on the time scale of a century, the decreased radiant output at sunspot maximum may be balanced by energy storage in the active features or by increased convective energy. A compensating change in the photospheric effective temperature of 1.1°K at sunspot maximum is also sufficient to give a constant solar radiant output.

Solar Thermal and Biomass Energy

Abstract: Part I: Sun Energy Chapter 1: The solar radiation The solar physics The solar constant The extraterrestrial radiation The position of the Sun in the celestial vault The solar radiation on the Earth's soil during clear sky days Instantaneous direct radiation received on a surface Instantaneous global radiation received on a surface Calculation of direct energy received on a surface The true solar time The diagram of solar trajectories The monthly average solar radiation on inclined surfaces Daily radiation on an inclined surface Hourly solar radiation on inclined surfaces The local radiation data retrieval Variation in the energy which can be intercepted by the position of the surfaces Chapter 2: Solar energy utilization Introduction Low-temperature solar thermal technology Medium-temperature solar thermal technology High-temperature solar thermal technology General bibliography and consulted websites - Part I Part II: Biomasses Energy Chapter 3: Biomasses identities Introduction Definition and classification Origin and nature Commercial forms Chapter 4: Energy from biomasses Biomass energy conversion Biochemical conversion Thermochemical conversion Chapter 5: Environmental aspects Reduction of emissions into the atmosphere