Modelling cosmic radiation events in the tree-ring radiocarbon record

Annually resolved measurements of the radiocarbon content in tree-rings have revealed rare sharp rises carbon-14 production. These ‘Miyake events’ are likely produced by increases cosmic radiation from Sun or other energetic astrophysical sources. The is not only circulated through Earth’s atmosphere and oceans, but also absorbed biosphere locked annual growth rings trees. To interpret high-resolution tree-ring therefore necessitates modelling entire global carbon cycle. Here, we introduce ‘ ticktack ’ ( https://github.com/SharmaLlama/ticktack/ ), first open-source Python package that connects box models cycle with modern Bayesian inference tools. We use this to analyse all public 14 C tree data, infer posterior parameters for six known Miyake events. They do show a consistent relationship solar cycle, several display extended durations challenge either geophysical models.