Clue from nature AD 1279

Radiocarbon rise 1279 to 1280: three labs, three sizes

Three labs, three sizes. Miyahara 2022 (asunaro, high precision): 1278 -11.67, 1279 -12.36, 1280 -9.16, 1281 -8.96 permil, a 3.2 permil jump into 1280, about 19 percent of the 774 event; they count it as confirmed. Brehm 2021 (oak ALTB05): a rise of about 5 permil around 1279 to 1281. Scifo 2024 (oak APT-C02): only 1.7 plus or minus 1.6. Timing rule from Miyahara et al. 2022: their asunaro (a Japanese conifer) photosynthesises from April and builds each ring mainly from April to August carbon of the same year. So a jump between ring N and ring N+1 means the burst of carbon-14 arrived after about August of year N and before about mid-year N+1. Oaks, by contrast, build their spring wood from the previous year's stored sugar, so oak records can lag a year.

How it connects

This clue from nature supports this hunch Korea's violet glow of 25 October 1279 falls in the window for the 1279 to 1280 radiocarbon jump, and the main paper missed it

This clue from nature is a clue for 1279 carbon-14 candidate

This clue from nature we read it in Brehm et al. 2021, Eleven-year solar cycles over the last millennium revealed by radiocarbon in tree rings, Nature Geoscience

This clue from nature we read it in Miyahara et al. 2022, Recurrent large-scale solar proton events before the onset of the Wolf grand solar minimum, Geophysical Research Letters 49 (free to read; read in full 25 Oct 2026; data on figshare doi 10.6084/m9.figshare.17096975)

This clue from nature we read it in Brehm et al. 2020, Radiocarbon measurements on tree rings 969 to 1933 AD, PANGAEA dataset (the raw numbers behind the 2021 paper)

This clue from nature we read it in Scifo et al. 2024, New data fails to replicate the small-scale radiocarbon anomalies in the early second millennium CE, Radiocarbon 66(3)