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

Abstract

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. Copyright 1997 by the American Geophysical Union.