Comparison of Total Solar Irradiance with NASA/National Solar Observatory Spectromagnetograph Data in Solar Cycles 22 and 23

Citations Over TimeTop 16% of 2003 papers

Abstract

NASA/National Solar Observatory Spectromagnetograph (SPM) data are compared with spacecraft measurements of total solar irradiance (TSI) variations for 8 yr beginning with the declining phase of solar cycle 22 and extending into the maximum of cycle 23. Previously reported conclusions based on a similar comparison for a shorter time period appear to be robust: three factors (sunspots, strong unipolar regions, and strong mixed-polarity regions) describe most of the variation in the SPM record, but only the first two are associated with TSI. Additionally, the residuals of a linear multiple regression of TSI against SPM observations over the entire 8 yr period show an unexplained, increasing, linear time variation with a rate of about 0.05 W m-2 yr-1. Separate regressions for the periods before and after 1996 January 1 show no unexplained trends but differ substantially in regression parameters. This behavior may reflect a solar source of TSI variations beyond sunspots or uncompensated nonsolar effects in one or both of the TSI and SPM data sets.

Related Papers

• → Geomagnetic activity indicates large amplitude for sunspot cycle 24(2006)143 cited
• → A brief review on the presentation of cycle 24, the first integrated solar cycle in the new millennium(2011)24 cited
• → Solar activity during first six years of solar cycle 24 and 23: a comparative study(2014)20 cited
• → A comparison of energetic solar proton events during the declining phase of four solar cycles (cycles 19–22)(1995)20 cited
• → Comparative study of solar cycles 22 to 24 in relation to solar output variability(2012)