Inference of Solar Irradiance Variability from Terrestrial Temperature Changes, 1880–1993: An Astrophysical Application of the Sun‐Climate Connection

Abstract

Information can be inferred on the timing and amplitude of solar total irradiance changes over 1880 1993 by simulating the global terrestrial surface temperature changes produced by these irradiance changes and comparing them with observed temperatures. The proles of solar irradiance variations used in the climate simulations are adopted from several di erent proxies : (1) the length of the sunspot cycle, (2) the mean sunspot number, and (3) a composite proxy that includes the two previous indicators plus the equatorial solar rotation rate, the fraction of penumbral spot coverage, and the rate of decay of the sunspot cycle. We use a seasonal energy-conservation climate/upwelling-di usion ocean model, forced by the assumed proles of solar total irradiance variations, combined with variations in anthropogenic greenhouse gases. Optimized cases imply total irradiance changes during 18801993 in the range 0.18%0.77%.