Causes of an AD 774-775 14C increase

TL;DR

This paper reevaluates the 14C increase in AD 774-775, suggesting the event's energy was smaller than previously thought but still significant, with implications for modern technology and understanding solar superflares.

Contribution

It provides a revised estimate of the coronal mass ejection energy during the AD 774-775 event, challenging prior claims of an extraordinarily large solar event.

Findings

The 14C production implies a smaller CME energy than previously estimated.

The event's energy exceeded the maximum of the 1859 Carrington Event.

Such an event could cause severe technological damage today.

Abstract

Atmospheric 14C production is a potential window into the energy of solar proton and other cosmic ray events. It was previously concluded that results from AD 774-775 are orders of magnitude greater than known solar events. We find that the coronal mass ejection energy based on 14C production is much smaller than claimed, but still substantially larger than the maximum historical Carrington Event of 1859. Such an event would cause great damage to modern technology, and in view of recent confirmation of superflares on solar-type stars, this issue merits attention.