Story perspectives

1200 Japanese Solar Storm 14× Strong, Tree Rings Reveal

6/5/2026

27 2

Summary

Story summary

A carbon-14 spike in Japanese tree rings indicates a solar storm about fourteen times stronger than the 1956 event.
Tree-ring analysis dated the spike to winter 1200–spring 1201 using Fujiwara no Teika’s diary and medieval records.
Researchers found early-13th-century solar cycles lasted only seven to eight years, shorter than today’s eleven-year cycle.
They say such reconstructions can improve prediction of future solar radiation hazards for space missions.

1 of 1

Story summary

A carbon-14 spike in Japanese tree rings indicates a solar storm about fourteen times stronger than the 1956 event.
Tree-ring analysis dated the spike to winter 1200–spring 1201 using Fujiwara no Teika’s diary and medieval records.
Researchers found early-13th-century solar cycles lasted only seven to eight years, shorter than today’s eleven-year cycle.
They say such reconstructions can improve prediction of future solar radiation hazards for space missions.