Continental-scale impact of bomb radiocarbon affects historical fossil fuel carbon dioxide reconstruction

<b>Source data underlying the figures and tables presented in the paper:</b><b>Continental-scale impact of bomb radiocarbon affects historical fossil fuel carbon dioxide reconstruction</b>Jing Li¹, Nannan Wei², Xu Wang³*, Pingyang Li¹, Yanmin Sun¹, Wenbiao Feng¹, Zhineng Cheng¹, Sanyuan Zhu¹, Weimin Wang⁴, Duohong Chen⁵, Shizhen Zhao¹, Guangcai Zhong¹, Guangyi Zhou², Jun Li¹, and Gan Zhang¹*¹State Key Laboratory of Advanced Environmental Technology, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China² School of Nuclear Science and Technology, University of South China, Hengyang 421001, China³Tropical Forestry Research Institute, Chinese Academy of Forestry, China, Guangzhou, Guangdong, 510520⁴Shenzhen Ecological and Environmental Monitoring Center of Guangdong Province<i>, </i>Shenzhen 518049<i>, </i>China⁵Environmental Key Laboratory of Regional Air Quality Monitoring, Ministry of Ecology and Environment, Guangdong Ecological and Environmental Monitoring Center, Guangzhou 510308, China^* Correspondence to: Gan Zhang ([e-mail]), Xu Wang ([e-mail])Tel.: [phone]. Fax: [phone].<br><b>Data in Figure 1 (Continental-scale impact of bomb 14C).xlsx</b>：The file contains three worksheets corresponding to the data presented in Figure 1, each addressing the radiocarbon (Δ14C) impact of historical nuclear bomb tests. Sheet “Figure 1a” presents Δ14C differences (ΔΔ14C) between background stations in China and compilations from corresponding latitudinal zones. Compilation data for NH-3, NH-2, and NH-1 are from Hua et al.1 The background stations in China include: Nanling (3000 km from Lop Nor, this study), Huangzhong (1300 km from Lop Nor, Xiong et al.), 2 Shangdianzi (2400 km from Lop Nor, Niu et al.), 3 Mingyin (2000 km from Lop Nor, Dai and Fan), 4 and Dailing (3200 km from Lop Nor, Dai and Fan). 5 All these stations use tree-ring samples, with comparisons conducted during the tree-ring growth periods: March–October at Nanling and Minying, May–August at Huangzhong, and May–September at Shangdianzi and Dailing. It also includes the yield of fission and fusion bomb tests at Semipalatinsk and Lop Nor.6 Sheet “Figure 1b” shows ΔΔ14C between background stations in China and European backgrounds (Vermunt and Jungfraujoch (JFJ), atmospheric data). The Vermunt data (1959–1983) is from Levin et al., and the JFJ data (1986–2015) is from Hammer and Levin. 7, 8 It also includes the yield of fission and fusion bomb tests at Semipalatinsk and Lop Nor.6. Sheet “Figure 1b” displays ΔΔ14C between European sites, zonal compilations and European backgrounds. These European sites including: Fruholmen (air, 1100 km from Novaya, Nydal and Lövseth), 9 Trondheim (air, 2100 km from Novaya, Nydal and Lövseth), 9 Trondelag (tree-ring, 2100 km from Novaya, Svarva et al.),10 Lindesnes (air, 2650 km from Novaya, Nydal and Lövseth), 9 Eastwen Jutland (tree-ring, 2700 km from Novaya, Kudsk et al.)11 and Niepolomice (tree-ring, 3100 km from Novaya, Rakowski et al.).12 Vermunt and JFJ are 3100 km from Novaya. It also includes the yield of fission and fusion bomb tests at Novaya.6<b>Data in Figure 2 (trajectory_frequency) folder: </b>The subfolder “Figure 2a–c – Lop Nor – HZ, SDZ, NL” contains trajectory frequency files for Huangzhong (HZ), Shangdianzi (SDZ), and Naling (NL) from 27 October to 26 November 1966, following the Lop Nor bomb test on 27 October 1966. The subfolder “Figure 2d–e – Semipalatinsk – HZ, NL” includes trajectory frequency files for Huangzhong and Naling from 22 August to 19 November 1957, during the Semipalatinsk bomb tests conducted between 22 August and 26 September 1957. The subfolder “Figure 2f – Novaya Zemlya – Fruholmen” contains trajectory frequency files for Fruholmen from 5 August 1962 to 1 January 1963, corresponding to the Novaya Zemlya tests carried out from 5 August to 25 December 1962.<b>Data in Figure 3 and SI Figure2 (Comparison of CO2ff estimations)</b><b>.xlsx:</b><b> </b>It comprises four worksheets presenting CO_2ff estimations for Xi’an, Beijing, Shenzhen, and Hengshan, respectively. . Each worksheet includes results derived using regional (Huangzhong (HZ), Shangdianzi (SDZ), Nanling (NL)), latitudinal (NH-1, NH-2, NH-3), and European (EU) background references. This data is both source data for Figure 3 and SI Figure2.<b>Data in SI Figure 1 (Δ14C curves).xlsx: </b>It contains Δ14C curves of Nanling compared to global stations. Tree-ring Δ14C datasets include Nanling (1921-2020, this study), Huangzhong (1957-2015)2 and Shangdianzi (1948-2018)3 in China, as well as of Olympic Peninsula, US (1921-1953) 13. Δ14C compilation of NH-3 is from Hua et al.1 Atmospheric Δ14C levels of European backgrounds, includes Vermunt (1959-1983) and Jungfraujoch (1986-2019) 7, 8.<b>Data in SI Figure 3 (Temperature and precipitation of Nanling).xlsx: </b>This file provides monthly temperature and precipitation records from a site near the Nanling tree ring sampling station.<b>Data in SI Table 3 (ecological half-life of bomb 14C).xlsx: </b>This file contains the ecological half-life (T1/2,e) of bomb 14C. The datasets in low-mid latitudinal zone include Nanling (this study), Mingyin,4 and compilations of NH-3 during March–October (Same with the growth period of Nanling trees).1 The datasets in middle latitudinal zone include Huangzhong, 2 and compilations of NH-2 during May–Augst (Same with the growth period of Huangzhong trees).1 The datasets in mid-high latitudinal zone include Shangdianzi,3 European backgrounds (Vermunt and JFJ)7, 8, and compilations of NH-1 during May–September (Same with the growth period of Huangzhong trees).1<b>Data in SI Table 5 (CO2ff differences).xlsx:</b> This file shows d<b>ifferences</b><b> in </b><b>CO</b>_{<strong>2ff</strong>}<b> estimation using various backgrounds. </b>The table includes: 1) the differences between regional backgrounds (Huangzhong, Shangdianzi, Nanling) and latitudinal backgrounds (NH-1, NH-2, NH-3); 2) the differences between regional backgrounds and European backgrounds (Vermunt and JFJ). The evaluated sites include Shenzhen and Hengshan, located within the NH-3 region; Xi’an, located within the NH-2 region; and Beijing, located within the NH-1 region.<b>Source 14C data.xlsx:</b> This file contains the ¹⁴C measurements generated in this study, presented across three worksheets corresponding to the Nanling background station, the Shenzhen urban station, and the Hengshan regional station.<b>Source CO2 data (Mauna Loa).xlsx:</b> CO2 data from Mauna Loa (MLO) which belong to Global Greenhouse Gas Reference Network were used in this study as the background CO2 levels, which available from 1970 to 2020 (https://gml.noaa.gov/ccgg/trends/).14<b>Statistical analysis code and data folder: </b>It contains the python code, source data and results that conducted the statistical analysis. The results including Data in SI Table 1-2 and 4. <b>References:</b>1. Hua, Q. et al. Atmospheric Radiocarbon for the Period 1950-2019. <i>Radiocarbon</i> <b>64</b>, 723-745 (2022).2. Xiong, X.H. et al. Time series of atmospheric Δ¹⁴CO₂ recorded in tree rings from Northwest China (1957-2015). <i>Chemosphere</i> <b>272</b> (2021).3. Niu, Z., Feng, X., Zhou, W., Wang, P. &amp; Cai, Q. Tree-ring Δ¹⁴C time series from 1948 to 2018 at a regional background site, China: Influences of atmospheric nuclear weapons tests and fossil fuel emissions. <i>Atmos. Environ.</i> <b>246</b>, 118156 (2021).4. Dai, K. &amp; Fan, C.Y. Bomb produced 14C content in tree rings grown at different latitudes. <i>Radiocarbon</i> <b>28</b>, 346-349 (1986).5. Dai, K., Qian, Y. &amp; Fan, C.Y. Bomb-produced ¹⁴C in tree rings. <i>Radiocarbon</i> <b>34</b>, 753-756 (1992).6. UNSCEAR United Nations Scientific Committee on the Effects of Atomic Radiation, UNSCEAR 2000 Report to the general assembly, with scientific annexes volume I: Sources and effects ofionizing radiation. (2000).7. Levin, I. et al. Delta ¹⁴CO₂ records from two sites in Central Europe. <i>CDIAC</i> (1997).8. Hammer, S. &amp; Levin, I. Monthly Mean Atmospheric Δ¹⁴CO₂ at Jungfraujoch and Schauinsland From 1986 to 2016. <i>heiDATA</i> <b>V2</b> (2017).9. Nydal, R. &amp; Lövseth, K. Carbon-14 measurements in atmospheric CO₂ from northern and southern hemisphere sites, 1962-1993. <i>Carbon Dioxide Information Analysis Center, World Data Center-A for Atmospheric Trace Gases, Oak Ridge National Laboratory, Tennessee.</i> (1996).10. Svarva, H. et al. The 1953–1965 rise in atmospheric bomb ¹⁴C in central Norway. <i>Radiocarbon</i> <b>61</b>, 1765-1774 (2019).11. Kudsk, S.G.K. et al. What is the carbon origin of early-wood? <i>Radiocarbon</i> <b>60</b>, 1457-1464 (2018).12. Rakowski, A.Z. et al. Radiocarbon method in environmental monitoring of CO₂ emission. <i>Nucl. Instrum. Meth. B.</i> <b>294</b>, 503-507 (2013).13. Stuiver, M. &amp; Quay, P.D. Atmospheric ¹⁴C Changes Resulting from Fossil-Fuel Co2 Release and Cosmic-Ray Flux Variability. <i>Earth. Planet. Sc. Lett.</i> <b>53</b>, 349-362 (1981).14. Thoning, K., Crotwell, A. &amp; Mund, J. Atmospheric Carbon Dioxide Dry Air Mole Fractions from continuous measurements at Mauna Loa, Hawaii, Barrow, Alaska, American Samoa and South Pole. 1973–2020. <i>Global Monitoring Laboratory (GML): Boulder, CO, USA</i> (2021).

<b>论文中图表对应的原始数据：</b><b>炸弹放射性碳的大陆尺度影响对历史化石燃料二氧化碳重建的作用</b>
李静¹，魏楠楠²，王旭³*，李平阳¹，孙彦敏¹，冯文彪¹，程志能¹，朱三元¹，王卫民⁴，陈多宏⁵，赵志能¹，钟广财¹，周广益²，李军¹，张干¹*
¹中国科学院广州地球化学研究所，先进环境技术国家重点实验室，广州 510640
²南华大学核科学技术学院，衡阳 421001
³中国林业科学研究院热带林业研究所，广州 510520
⁴广东省深圳生态环境监测中心站，深圳 518049
⁵生态环境部区域空气质量监测重点实验室，广东省生态环境监测中心，广州 510308
^*通讯作者：张干（[e-mail]），王旭（[e-mail]）
电话：[phone]；传真：[phone]
<br><b>图1（炸弹14C的大陆尺度影响）相关数据.xlsx：</b>该文件包含3个工作表，对应图1展示的数据，每个工作表均涉及历史核炸弹试验产生的放射性碳（Δ14C）影响。工作表“Figure1a”呈现中国背景站点与对应纬度带汇编数据之间的放射性碳偏差差值（ΔΔ14C）。北半球3带（NH-3）、北半球2带（NH-2）、北半球1带（NH-1）的汇编数据来自Hua等¹。中国背景站点包括：南岭（距罗布泊3000公里，本研究）、湟中（距罗布泊1300公里，Xiong等²）、上甸子（距罗布泊2400公里，Niu等³）、明银（距罗布泊2000公里，Dai和Fan⁴）、带岭（距罗布泊3200公里，Dai和Fan⁵）。所有站点均采用树轮样本，对比时段为树轮生长季：南岭和明银为3-10月，湟中为5-8月，上甸子和带岭为5-9月。该工作表还包含塞米巴拉金斯克和罗布泊核试验的裂变与聚变炸弹当量数据⁶。工作表“Figure1b”展示中国背景站点与欧洲背景（Vermunt和少女峰（JFJ）大气数据）之间的ΔΔ14C。Vermunt数据（1959-1983）来自Levin等⁷，JFJ数据（1986-2015）来自Hammer和Levin⁸，同时包含塞米巴拉金斯克和罗布泊核试验的当量数据⁶。工作表“Figure1b”还呈现欧洲站点、纬度带汇编数据与欧洲背景之间的ΔΔ14C。这些欧洲站点包括：Fruholmen（大气，距新地岛1100公里，Nydal和Lövseth⁹）、Trondheim（大气，距新地岛2100公里，Nydal和Lövseth⁹）、Trondelag（树轮，距新地岛2100公里，Svarva等¹⁰）、Lindesnes（大气，距新地岛2650公里，Nydal和Lövseth⁹）、Eastwen Jutland（树轮，距新地岛2700公里，Kudsk等¹¹）、Niepolomice（树轮，距新地岛3100公里，Rakowski等¹²）。Vermunt和JFJ距新地岛3100公里，该工作表还包含新地岛核试验的当量数据⁶。
<b>图2（轨迹频率）文件夹中的数据：</b>子文件夹“Figure2a–c – 罗布泊 – HZ、SDZ、NL”包含1966年10月27日罗布泊核试验后，湟中（HZ）、上甸子（SDZ）、南岭（NL）在1966年10月27日至11月26日期间的轨迹频率文件。子文件夹“Figure2d–e – 塞米巴拉金斯克 – HZ、NL”包含1957年8月22日至9月26日塞米巴拉金斯克核试验期间，湟中与南岭在1957年8月22日至11月19日的轨迹频率文件。子文件夹“Figure2f – 新地岛 – Fruholmen”包含1962年8月5日至12月25日新地岛核试验期间，Fruholmen在1962年8月5日至1963年1月1日的轨迹频率文件。
<b>图3及补充信息图2（化石燃料二氧化碳（CO₂ff）估算对比）相关数据.xlsx：</b>包含4个工作表，分别呈现西安、北京、深圳、衡山的CO₂ff估算结果。每个工作表均包含基于区域背景（湟中（HZ）、上甸子（SDZ）、南岭（NL））、纬度带背景（NH-1、NH-2、NH-3）和欧洲背景（EU）的估算结果，该数据同时为图3和补充信息图2的原始数据。
<b>补充信息图1（Δ14C曲线）相关数据.xlsx：</b>包含南岭与全球站点的Δ14C曲线数据。树轮Δ14C数据集包括中国的南岭（1921-2020，本研究）、湟中（1957-2015²）、上甸子（1948-2018³），以及美国奥林匹克半岛（1921-1953¹³）。NH-3纬度带的Δ14C汇编数据来自Hua等¹。欧洲背景的大气Δ14C数据包括Vermunt（1959-1983⁷）和JFJ（1986-2019⁸）。
<b>补充信息表3（炸弹14C的生态半衰期）相关数据.xlsx：</b>包含炸弹14C的生态半衰期（T1/2,e）数据。低中纬度带数据集包括南岭（本研究）、明银⁴及NH-3纬度带3-10月（与南岭树轮生长季一致）的汇编数据¹。中纬度带数据集包括湟中²及NH-2纬度带5-8月（与湟中树轮生长季一致）的汇编数据¹。中高纬度带数据集包括上甸子³、欧洲背景（Vermunt和JFJ^7,8）及NH-1纬度带5-9月（与湟中树轮生长季一致）的汇编数据¹。
<b>补充信息表5（CO₂ff估算差异）相关数据.xlsx：</b>展示不同背景下CO₂ff估算结果的差异，包括：1）区域背景（湟中、上甸子、南岭）与纬度带背景（NH-1、NH-2、NH-3）的差异；2）区域背景与欧洲背景（Vermunt和JFJ）的差异。评估站点包括NH-3区域的深圳和衡山、NH-2区域的西安、NH-1区域的北京。
<b>原始14C数据.xlsx：</b>包含本研究生成的14C测量数据，分为三个工作表，对应南岭背景站、深圳城市站、衡山区域站。
<b>原始CO₂数据（莫纳罗亚）.xlsx：</b>本研究采用全球温室气体参考网络的莫纳罗亚（MLO）CO₂数据作为背景CO₂水平，时间范围为1970-2020（网址：https://gml.noaa.gov/ccgg/trends/¹⁴）。
<b>统计分析代码与数据文件夹：</b>包含用于统计分析的Python代码、原始数据及结果，结果对应补充信息表1-2和4。
<b>参考文献：</b>
1. Hua等. 1950-2019年大气放射性碳. 《放射性碳》<b>64</b>：723-745（2022）.
2. Xiong等. 中国西北地区树轮记录的大气Δ14CO₂时间序列（1957-2015）. 《化学圈》<b>272</b>（2021）.
3. Niu等. 中国区域背景站点树轮Δ14C时间序列（1948-2018）：大气核试验与化石燃料排放的影响. 《大气环境》<b>246</b>：118156（2021）.
4. Dai和Fan. 不同纬度树轮中的炸弹产生14C含量. 《放射性碳》<b>28</b>：346-349（1986）.
5. Dai等. 树轮中的炸弹产生14C. 《放射性碳》<b>34</b>：753-756（1992）.
6. 联合国原子辐射影响科学委员会. 2000年向大会提交的报告，附科学附件第一卷《电离辐射的来源与影响》（2000）.
7. Levin等. 中欧两个站点的Δ14CO₂记录. 二氧化碳信息分析中心（1997）.
8. Hammer和Levin. 1986-2016年少女峰与绍因斯兰的月均大气Δ14CO₂. heiDATA数据库<b>V2</b>（2017）.
9. Nydal和Lövseth. 1962-1993年南北半球站点大气CO₂中的14C测量. 二氧化碳信息分析中心，全球大气痕量气体数据中心-A，橡树岭国家实验室（1996）.
10. Svarva等. 1953-1965年挪威中部大气炸弹14C的上升趋势. 《放射性碳》<b>61</b>：1765-1774（2019）.
11. Kudsk等. 早材的碳来源是什么？《放射性碳》<b>60</b>：1457-1464（2018）.
12. Rakowski等. 14C方法在CO₂排放环境监测中的应用. 《核仪器与方法B》<b>294</b>：503-507（2013）.
13. Stuiver和Quay. 化石燃料CO₂释放与宇宙射线通量变化导致的大气14C变化. 《地球与行星科学快报》<b>53</b>：349-362（1981）.
14. Thoning等. 莫纳罗亚、巴罗、美属萨摩亚和南极点的大气CO₂干空气摩尔分数连续测量（1973-2020）. 全球监测实验室（GML）：美国科罗拉多州博尔德（2021）.