我国西北地区树轮记录的大气Δ14CO2变化历史数据集（1957-2015）

放射性碳（14C）是重要的测年工具，同时也被广泛应用于碳循环的研究，但这些应用都离不开可靠的历史时期的大气Δ14CO2记录，特别是1950年以来的现代样品的定年需要可靠的大气Δ14CO2记录。由于受到人类活动（核爆效应和苏斯效应）的影响，上世纪五十年代以来大气14CO2发生了急剧的变化，然而，我国该时期的大气Δ14CO2记录十分匮乏。本研究利用青藏高原东北缘，受人类活动影响较小区域的一个青海云杉树轮盘样品（采样点经纬度：36.27° N，101.67° E），重建了该地区1957-2015年大气14CO2时间序列。结果表明该记录总体上高于北半球中高纬区域记录的平均水平。所重建的核爆曲线峰值出现在1964年，高于东亚近似纬度区域的其他树轮记录的核爆峰值，很可能是受到了前苏联塞米帕拉金斯克核试验场核爆试验的影响。我们还发现，我国罗布泊核试验场于1964-1980年期间开展的大气核爆试验并未对该记录产生明显的扰动。区域苏斯效应（Suess effect）的影响在2001年之后才开始显现，可能与西部大开发战略的实施促进了区域经济快速发展有关，但2015年的化石源CO2浓度仍明显低于同时期城市化石源CO2浓度水平，说明该区域受到化石燃料CO2排放的影响较小。

Radiocarbon (¹⁴C) is a critical dating tool and is widely applied in carbon cycle research. However, all these applications depend on reliable atmospheric Δ¹⁴CO₂ records from historical periods; specifically, dating modern samples since 1950 requires credible atmospheric Δ¹⁴CO₂ data. Affected by human activities (including nuclear bomb effects and the Suess effect), atmospheric ¹⁴CO₂ has undergone dramatic changes since the 1950s. Nevertheless, atmospheric Δ¹⁴CO₂ records for this period in China remain extremely scarce. In this study, we reconstructed the atmospheric ¹⁴CO₂ time series for the period 1957–2015 using a tree-ring disc sample of Picea crassifolia collected from a region with minimal human disturbance on the northeastern margin of the Qinghai-Tibet Plateau (sampling site coordinates: 36.27° N, 101.67° E). The results indicate that this record is generally higher than the average level of records from mid-to-high latitudes of the Northern Hemisphere. The reconstructed nuclear bomb-related ¹⁴CO₂ peak occurred in 1964, which exceeds the nuclear peak values of other tree-ring records from East Asian regions at similar latitudes, most likely due to the influence of nuclear tests conducted at the former Soviet Union’s Semipalatinsk Nuclear Test Site. We also found that atmospheric nuclear tests carried out at China’s Lop Nur Nuclear Test Site between 1964 and 1980 did not cause significant perturbations to this record. The impact of the regional Suess effect only became apparent after 2001, which may be linked to the rapid regional economic development driven by the implementation of China’s Western Development Strategy. However, the fossil-fuel-derived CO₂ concentration in 2015 was still significantly lower than the urban fossil-fuel-derived CO₂ concentration levels of the same period, suggesting that this region is relatively less affected by fossil fuel CO₂ emissions.

搜集汇总

背景与挑战

背景概述

该数据集通过中国西北部青海省的一个青海云杉树轮样品，重建了1957-2015年大气Δ14CO2变化历史，用于研究碳循环和核爆效应。数据显示记录高于北半球中高纬平均水平，核爆峰值在1964年可能受前苏联核试验影响，而区域苏斯效应在2001年后才显现，表明受化石燃料排放影响较小。数据集涵盖时间序列数据，主题涉及树轮、Δ14C和大气科学，数据量较小，适用于气候变化和环境污染研究。