As part of the ongoing effort to improve the Northern Hemisphere radiocarbon (14C) calibration curve, this study investigates the period of 856 BC to 626 BC (2805–2575 yr BP) with a total of 403 single-year 14C measurements. In this age range, IntCal13 was constructed largely from German and Irish oak as well as Californian bristlecone pine 14C dates, with most samples measured with a 10-yr resolution. The new data presented here is the first atmospheric 14C single-year record of the older end of the Hallstatt plateau based on an absolutely dated tree-ring chronology. The data helped reveal a major solar proton event (SPE) which caused a spike in the production rate of cosmogenic radionuclides around 2610/2609 BP. This production event is thought to have reached a magnitude similar to the 774/775 AD production event but has remained undetected due to averaging effects in the decadal calibration data. The record leading up to the 2610/2609 BP event reveals a 11-yr solar cycle with varying cyclicity. Features of the new data and the benefits of higher resolution calibration are discussed.

中文翻译：

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公元前 856 年至公元前 626 年哈尔施塔特高原初期的单年德国橡木和加利福尼亚刺尾松 14C 数据

作为改善北半球放射性碳的持续努力的一部分（14C) 校准曲线，本研究调查了公元前 856 年至公元前 626 年（2805-2575 年 BP）的时期，总共 403 个单年14C 测量。在这个年龄范围内，IntCal13 主要由德国和爱尔兰橡木以及加利福尼亚刺尾松构成14C 日期，大多数样品的测量分辨率为 10 年。这里提供的新数据是第一个大气14C 基于绝对过时的年轮年表的哈尔施塔特高原较旧端的单年记录。这些数据帮助揭示了一个重大的太阳质子事件 (SPE)，该事件导致了 2610/2609 BP 左右宇宙成因放射性核素的产生率飙升。该生产事件被认为已达到与 774/775 AD 生产事件相似的量级，但由于十年校准数据的平均效应而仍未被发现。导致 2610/2609 BP 事件的记录揭示了一个 11 年的太阳周期，具有不同的周期性。讨论了新数据的特点和更高分辨率校准的好处。