Solar constant

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

SORCE Level 3 Total Solar Irradiance Daily Average V016

Abstract: the total solar irradiance tsi data set sor3tsid contains the total solar irradiance a k a solar constant data collected by the total irradiance monitor tim instrument covering the full wavelength spectrum averaged at daily intervals the data are normalized to one astronomical unit 1 au the tim instrument measures the total solar irradiance tsi monitoring changes in incident sunlight to the earth s atmosphere using an ambient temperature active cavity radiometer to a designed absolute accuracy of 100 parts per million ppm 1 ppm 0 0001 at 1 sigma and a precision and long term relative accuracy of 10 ppm per year due to the small size these data and to maximize ease of use to end users each delivered tsi product contains science results for the entire mission updates to level 3 tsi data occur monthly in order to reduce repeated delivery of data

Sunsets and solar diameter measurement

Abstract: A sunset over the sea surface offers the possibility to chronometrate a solar transit across the horizon. The vertical solar diameter is proportional to the duration of the sunset, the cosine of the azimuth and the cosine of the latitude of the observing site. The same formula applies to every circle of equal height, called in arabic almucantarat, and it is exploited in the measurements of the solar diameter made with the Danjon's solar astrolabes. The analogies between sunsets and astrolabes observations are presented, showing advantages and sources of errors of these methods of solar astrometry.

Solar Constant Data from Earth Radiation Budget Measurements

Abstract: At present, solar total irradiance measurements are made from four satellites using electrically self calibrating pyrheliometers, as a part of the earth radiation budget measurement programs. The Earth Radiation Budget (ERB) mission onboard Nimbus-7 spacecraft (Nimbus/ERB) started solar total irradiance measurements in November 1978, and is still obtaining irradiance data on every orbit, daily. The Earth Radiation Budget Experiment (ERBE) solar monitors onboard Earth Radiation Budget Satellite (ERBS), NOAA-9 and NOAA-10 started solar total irradiance measurements in October 1984, January 1985, and October 1986, respectively. Our knowledge of solar total irradiance and its variability has grown remarkably during the past few years, as a result of the above measurements, and the high precision data obtained from Solar Maximum Mission/Active Cavity Radiometer Irradiance Monitor-1 (SMM/ACRIM-1). The results from a comparative study of the solar constant data available from the above missions are presented. The solar constant value derived from the sensors agree within the uncertainty associated with absolute pyrheliometers available at present. An attempt will be made to correlate the solar irradiance variability with other solar parameters. The measurements from Nimbus-7/ERB started November 1978, as the solar cycle 21 was increasing in activity. The solar luminosity reached a maximum in the spring of 1979. The irradiance then decreased slowly to a minimum which lasted from 1984 through 1986. The irradiance is presently increasing towards a new maximum. It appears that the solar constant value follow an eleven year cycle.

The solar constant and the solar spectrum as measured from a high altitude research aircraft.

Abstract: Solar constant and solar spectral irradiance measurements from high altitude research aircraft, discussing radiation measuring instruments