SORCE

INTRO

The measurements provided by SORCE specifically address long-term climate change, natural variability and enhanced climate prediction, and atmospheric ozone and UV-B radiation. These measurements are critical to studies of the Sun; its effect on our Earth system; and its influence on humankind.


Total Irradiance Monitor (TIM)

TIM will measure the total amount of radiation coming from the Sun. The sensor uses what is known as an absolute radiometer and houses four cone-shaped cavities. One of the cavities has an oscillating shutter that allows direct sunlight to shine into one of the cones. The material in the cone absorbs nearly all the Sun’s energy and heats up. By measuring the voltage needed to bring this heated cone back to the same temperature as one of the other “reference” cones, which are kept at a constant temperature, the instrument can obtain an extremely accurate reading of the TSI in watts.


Spectral Irradiance Monitor(SIM)

The SIM instrument will take contiguous spectral readings of the near UV, visible, and near infrared portions of the solar spectrum, from 200 to 2000 nm, which includes the peak of the solar spectrum and together add up to more than 90% of the Total Solar Irradiance. Scientists will be recording measured energy in separate bands of ultraviolet light, violet light, blue light, yellow light, green light, red light, and near infrared light coming from the Sun.SIM will be the first instrument in orbit to take readings of the full spectrum of visible and near-infrared solar radiation.


Solar Stellar Comparison Experiment (SOLSTICE)

The Solar Stellar Irradiance Comparison Experiment (SOLSTICE) is one of four solar irradiance measurement experiments that was launched as part of the Solar Radiation and Climate Experiment (SORCE) on January 25, 2003. SORCE SOLSTICE is a follow-on to the very successful SOLSTICE launched aboard the Upper Atmospheric Research Satellite (UARS) in 1991 [Rottman et al., 1993]. The new SOLSTICE makes daily solar ultraviolet (115-320 nm) irradiance measurements and compares them to the irradiance from an ensemble of 18 stable early-type stars. This approach provides an accurate monitor of instrument in-flight performance and provides a basis for solar- stellar irradiance comparison for future generations.




XUV photometer system(XPS)

The XPS instrument will take readings in the “far” ultraviolet, with wavelengths much shorter than seen by SOLSTICE, and down into the “soft” X-ray region. This was a planned passivation event for SORCE now that the new NASA Total and Spectral Solar Irradiance Sensor (TSIS-1) mission has had its required overlap with SORCE. The NASA Solar Radiation and Climate Experiment (SORCE) science mission ended on February 25, 2020 after completing more than 17 years of excellent observations of the total solar irradiance (TSI)