In order to study radiocarbon levels at a clean air location in Slovakia with no significant local anthropogenic effects, we took tree ring samples from a tree in the vicinity of Jasná recreational area in the Low Tatras region in the central part of Slovakia. There are no significant local fossil fuel emission sources, so these samples represent a regional clean air background important for 14C studies in Slovakia and Central Europe. The growth rings from the sampled tree (European spruce, Picea abies) cover the period from 1911 to 2016. The first part of the data (1911-1952) represents natural radiocarbon levels influenced by Suess effect. The following period exhibits an increase in radiocarbon levels due to atmospheric nuclear weapons tests (Δ14C maximum of 850‰ in 1964), and then a gradual decrease characterized by an exponential trend with time constant of 14.3 ± 0.5 years. The Δ14C data from Jasná was used as a reference for comparison with two previously reported modern tree ring data sets from Slovakia. This comparison showed that radiocarbon levels at both locations are lower than clean air reference values, indicating the influence of local fossil fuel emissions.

中文翻译：

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在斯洛伐克的一个清洁空气区域的年轮中的放射性碳。

为了研究斯洛伐克清洁空气场所的放射性碳水平，而没有明显的当地人为影响，我们从斯洛伐克中部Low Tatras地区Jasná休闲区附近的一棵树上采集了年轮样本。当地没有重要的化石燃料排放源，因此这些样品代表了对斯洛伐克和中欧的14C研究具有重要意义的区域清洁空气背景。采样树（欧洲云杉，云杉云杉）的年轮覆盖了1911年至2016年。数据的第一部分（1911-1952）代表受Suess效应影响的天然放射性碳水平。接下来的时期由于大气核武器试验而导致放射性碳水平上升（1964年的最高14‰Δ14C），然后逐渐下降，其特征是时间常数为14.3±0.5年的指数趋势。来自Jasná的Δ14C数据被用作与斯洛伐克先前报告的两个现代树木年轮数据集进行比较的参考。该比较表明，两个地点的放射性碳水平均低于清洁空气参考值，表明了当地化石燃料排放的影响。