Correcting the Zurich and International Sunspot Counts from 1849 to Present

Louisiana State University, Baton Rouge LA

Investigators

Abstract

This is a study to correct the Zurich and International sunspot numbers by applying corrections based on improved coefficients. An accurate sunspot record is vital for evaluating solar effects on global warming (to determine the relative importance of solar and greenhouse effects), for predicting future solar activity, and for all Sun-Earth connection studies on time scales from decades to centuries. Virtually all studies of solar activity on time scales from a few decades to a few centuries are based on the Zurich and International sunspot counts. Yet these have previously unrecognized systematic errors on all time scales from months to centuries with errors by up to a factor of two. These are caused by the normal variations of the K-coefficients for the Standard Observers in Zurich and Locarno. The Standard Observers (who are defined to have K=0.60) are known to be nonstandard because their measured K-coefficients varied by a factor of 2 before they became the definition of standard and because the K-coefficients for all observers worldwide vary up-and-down in synchronization with large amplitude. The inevitable result is that the Zurich and International sunspot counts have corresponding errors on all time scales by up to a factor of two. In this study, a complete error analysis will be made so that actual one-sigma error bars can be determined for all sunspot counts and their derived quantities. The primary data product will be a fully corrected sunspot count from 1849 to present. The improved counts will lead to better predictions of future solar activity on a cycle-by-cycle basis; and this will be important for spacecraft launch/reboost/reentry planning and climate forecasters. The improved counts may substantially change the conclusions of the importance of solar activity on the observed global warming over the last century. Judging the effects of greenhouse gases versus solar activity is important for environmental economics and hence politics.