Solar spectral irradiance, 120 to 190nm, October 13, 1981 ‐ January 3, 1982

Abstract

Beginning on October 13, 1981 a two channel spectrometer aboard the Solar Mesosphere Explorer has been obtaining daily measurements of full disc solar irradiance. These observations cover the spectral interval 120 to 305nm with ∽ .75nm spectral resolution. The relative accuracy of the measurements from day to day over the first three solar rotations is approximately 1%. In this report we present analyses of Lyman‐alpha, the integrated Schumann‐Runge continuum (130‐175nm), and the integrated Schumann‐Runge bands (175 to 190nm). All three show a clear variability related primarily to the 27‐day solar rotation period. Correlations of these three values of solar irradiance to ground‐based indices of solar activity, 10.7cm flux and sunspot number, are presented.