Solar hydrogen Lyman-α variation during solar cycles 21 and 22

A full‐disk, line‐integrated solar Lyman‐α dataset is presented that spans two solar cycles. The dataset is created partially from AE‐E and SME data that is scaled to the Pioneer Venus Orbiter Ultraviolet Spectrometer (PVOUVS) upwind Lyman‐α sky background data which is converted to a solar surrogate. PVOUVS measurements overlap AE‐E, SME, and UARS observing periods and are calibrated to UARS/SOLSTICE irradiance units at 1 AU. The scaled AE‐E/SME, the SOLSTICE, and the PVOUVS surrogate data in the interim between the satellites collectively form a composite dataset with a quiet sun value of 3.0±0.1 × 1011 photons cm−2s−1 common for three solar minima and a solar maximum value of 6.75±0.25 × 1011 photons cm−2s−1 common to cycles 21 and 22.