NASA's Total and Spectral solar Irradiance Sensor, or TSIS-1, is a mission to measure the sun's energy input to Earth. Various satellites have captured a continuous record of this solar energy input since 1978. TSIS-1 sensors advance previous measurements, enabling scientists to study the sun's natural influence on Earth's ozone layer, atmospheric circulation, clouds, and ecosystems. These observations are essential for a scientific understanding of the effects of solar variability on the Earth system.
NASA Goddard Space Flight Center manages the project. The University of Colorado's Laboratory for Atmospheric and Space Physics (LASP) built both instruments and provides mission operations. The International Space Station carries TSIS-1.
Earth's energy budget is a metaphor for the delicate equilibrium between energy received from The Sun versus energy radiated back out in to space. Research into precise details of Earth's energy budget is vital for understanding how the planet's climate may be changing, as well as variabilities in solar energy output. Missions like NASA's TSIS will help scientists keep a close watch.
TSIS-1 makes two key measurements: total solar irradiance, or TSI, the sun's total energy input into Earth, and solar spectral irradiance (SSI), the distribution of the sun's energy input across ultraviolet, visible, and infrared wavelengths of light. TSI measurements are needed to quantify the solar variations in the total amount of energy input to the Earth. SSI measurements are also vital because different wavelengths of light are absorbed by different parts of the atmosphere.
NASA's Total and Spectral solar Irradiance Sensor, or TSIS-1, will measure the total amount of solar energy input to Earth as well as the distribution of The Sun's energy input across a wide range of wavelengths. In this animation we see how various wavelengths of light are partially reflected into space at different places in the column of atmosphere above the ground.
The sensors of TSIS-1, the Total Irradiance Monitor (TIM) and the Spectral Irradiance Monitor (SIM), are significantly improved versions of sensors included on NASA’s Solar Radiation and Climate Experiment (SORCE) mission launched in 2003. Both sensors are more accurate and more precise than their predecessors.