405 Year Sunspot Record Revised and Newly Calibrated

Credits: SILSO Data - Royal Observatory of Belgium, Brussels

Dating back to Galileo and the invention of the telescope, the 405-year solar sunspot record is the longest continuously monitored daily measurement in all of science. Studies into sunspots, solar and planetary cycles corresponding with trade cycles, crop prices and shifts in the markets have accelerated since the 19th century. Now, on July 1st, 2015 the official sunspot record underwent a complete overhaul for the first time since it was created by Swiss astronomer Rudolf Wolf in 1849. The newly calibrated record is likely to have implications in many diverse scientific disciplines including financial astrology.

Yet, this important change to one of science’s most fundamental measurements went literally unnoticed (HERE & HERE) Two sunspot record time series were recalibrated: The first is the traditional International Sunspot Number (ISN) record most people are familiar with. The second is the more physically meaningful group number. Groups have always been counted as part of the ISN. The newly released group number update redefines and corrects defects in the original 1998 version. The newly rebuilt group number time series shows that solar activity is considerably more ‘even’ over its 405-year history than previously thought. Formerly, it looked as though sunspot activity in the past was much weaker than at present, especially prior to 1890. Counting inconsistencies artificially created that non-existent effect. The rebuilt record contains four distinctive dips in solar activity that occur roughly every 100 years.