Solar Irradiance Datasets

TSI quicklook figure showing solar irradiance measurements since 1978

The total solar irradiance (TSI), which provides the net energy powering the Earth's climate system, has been measured from a series of overlapping radiometrically accurate space-borne instruments giving this uninterrupted record of solar forcing since 1978. Offsets between instruments are due to calibration differences, with the newer instruments being more accurate. The measurements show variations of ~0.1% over the 11-year solar cycle (indicated by the sunspot number plotted in black) and 0.1 to 0.3% on 27-day solar-rotation time periods.

Updated monthly

Data Access