Observations of radiocarbon (14C) in Earth’s atmosphere and other carbon reservoirs are important to quantify exchanges of CO2 between reservoirs. The amount of 14C is commonly reported in the so-called Delta notation, i.e., Δ14C, the decay- and fractionation-corrected departure of the ratio of 14C to total C from that ratio in an absolute international standard; this Delta notation permits direct comparison of 14C/C ratios in the several reservoirs. However, as Δ14C of atmospheric CO2, Δ14CO2 is based on the ratio of 14CO2 to total atmospheric CO2, its value can and does change not just because of change in the amount of atmospheric14CO2 but also because of change in the amount of total atmospheric CO2, complicating ascription of change in Δ14CO2 to change in one or the other quantity. Here we suggest that presentation of atmospheric 14CO2 amount as mole fraction relative to dry air (moles of 14CO2 per moles of dry air in Earth’s atmosphere), or as moles or molecules of 14CO2 in Earth’s atmosphere, all readily calculated from Δ14CO2 and the amount of atmospheric CO2 (with slight dependence on δ13CO2), complements presentation only as Δ14CO2, and can provide valuable insight into the evolving budget and distribution of atmospheric 14CO2.

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讨论：大气 14CO2 数据的呈现

放射性碳的观测（14C）地球大气和其他碳库中的二氧化碳对于量化二氧化碳交换非常重要2水库之间。大量的14C 通常以所谓的 Delta 表示法表示，即 Δ14C，衰减和分馏校正的比率偏差14C 与总 C 的比值符合绝对国际标准；这种 Delta 表示法允许直接比较14几个储层中的 C/C 比率。然而，随着 Δ14大气中CO的C2, Δ14一氧化碳2是基于以下比率14一氧化碳2大气CO总量2，它的值可以而且确实会变化，不仅仅是因为大气量的变化14一氧化碳2还因为大气中二氧化碳总量的变化2，使 Δ 的变化归因变得复杂14一氧化碳2改变一个或另一个数量。在这里我们建议大气的呈现14一氧化碳2相对于干燥空气的摩尔分数（摩尔数）14一氧化碳2每摩尔地球大气中的干燥空气），或作为摩尔或分子14一氧化碳2在地球大气层中，所有这些都可以很容易地从 Δ 计算出来14一氧化碳2和大气中二氧化碳的含量2（轻微依赖于 δ13一氧化碳2)，仅补充表示为 Δ14一氧化碳2，并且可以为不断变化的大气预算和分布提供有价值的见解14一氧化碳2。