1000-year sunspot series

The relative sunspot number (SN) is the primary index of solar activity back to 1610. For earlier periods, SN can be reconstructed from the concentrations of cosmogenic...相对太阳黑子数（Relative Sunspot Number，SN）是可追溯至1610年的首要太阳活动指数。针对更早的历史时期，可通过宇宙成因（cosmogenic）组分的浓度重建SN数值。