The Solar Cycle 23 – 24 Minimum. A Benchmark in Solar Variability and Effects in the Heliosphere

Given the numerous ground-based and space-based experiments producing the database for the Cycle 23 – 24 Minimum epoch from September 2008 to May 2009, we have an extraordinary opportunity to understand its effects throughout the heliosphere. We use solar radiative output in this period to obtain minimum values for three measures of the Sun’s radiative output: the total solar irradiance, the Mg ii index, and the 10.7 cm solar radio flux. The derived values are included in the research summaries as a means to exchange ideas and data for this long minimum in solar activity.