Sulfur isotopes quantify the impact of anthropogenic activities on industrial-era Arctic sulfate in a Greenland ice core
Sulfur isotopes quantify the impact of anthropogenic activities on industrial-era Arctic sulfate in a Greenland ice core
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DOI：
10.1088/1748-9326/acdc3d
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发表时间：
2023-06
影响因子：
6.7
通讯作者：
U. Jongebloed;A. Schauer;S. Hattori;J. Cole‐Dai;C. Larrick;Sara Salimi;Shana R Edouard;L. Geng;B. Alexander
中科院分区：
文献类型：
--
作者：
U. Jongebloed;A. Schauer;S. Hattori;J. Cole‐Dai;C. Larrick;Sara Salimi;Shana R Edouard;L. Geng;B. Alexander
据估计，人为的硫酸盐气溶胶抵消了北极地区60%的温室气体引起的变暖，北极地区的变暖速度是世界其他地区的四倍。然而，硫酸盐辐射强迫的估计仍然不确定，因为人为源与自然源对总硫酸盐气溶胶的相对贡献尚不清楚。在这里，我们测量了1850年至2006年格陵兰冰芯中硫酸盐的硫同位素，以量化人为硫排放对冰芯硫酸盐的贡献。我们利用基林图确定了人为硫同位素特征（δ34Santhro = +2.9±0.3‰），并与石油和煤的硫同位素测量结果进行了比较。利用δ34Santhro，我们定量了从天然硫酸盐中分离出来的人为硫酸盐浓度。在1960 - 1990年的人为排放峰值期间，人为硫酸盐浓度增加到非海盐硫酸盐的67±7%(65.1±20.2µg kg - 1)，而在1996 - 2006年期间，人为硫酸盐浓度下降到非海盐硫酸盐的45±11%（25.4±12.8µg kg - 1）。这些观测提供了第一个与自然来源（如火山、二甲基硫化物）不同的人为硫酸盐的长期记录，并可用于评估工业时代人为硫酸盐气溶胶组分和辐射强迫的模式特征。
Anthropogenic sulfate aerosols are estimated to have offset 60% of greenhouse-gas-induced warming in the Arctic, a region warming four times faster than the rest of the world. However, sulfate radiative forcing estimates remain uncertain because the relative contributions from anthropogenic versus natural sources to total sulfate aerosols are unknown. Here we measure sulfur isotopes of sulfate in a Summit, Greenland ice core from 1850 to 2006 CE to quantify the contribution of anthropogenic sulfur emissions to ice core sulfate. We use a Keeling plot to determine the anthropogenic sulfur isotopic signature (δ34Santhro = +2.9 ± 0.3 ‰), and compare this result to a compilation of sulfur isotope measurements of oil and coal. Using δ34Santhro, we quantify anthropogenic sulfate concentration separated from natural sulfate. Anthropogenic sulfate concentration increases to 67 ± 7% of non-sea-salt sulfate (65.1 ± 20.2 µg kg−1) during peak anthropogenic emissions from 1960 to 1990 and decreases to 45 ± 11% of non-sea-salt sulfate (25.4 ± 12.8 µg kg−1) from 1996 to 2006. These observations provide the first long-term record of anthropogenic sulfate distinguished from natural sources (e.g. volcanoes, dimethyl sulfide), and can be used to evaluate model characterization of anthropogenic sulfate aerosol fraction and radiative forcing over the industrial era.