Anthropogenic activities have significantly enhanced atmospheric metal inputs to the ocean, which has potentially important consequences for marine ecosystems. This study assesses the potential of Zn and Cu isotope compositions to distinguish between natural and anthropogenic atmospheric inputs of these metals to the surface ocean. To this end, the isotopic compositions of Zn and Cu in aerosols collected from the eastern tropical Atlantic Ocean on the GEOTRACES GA06 cruise are examined. Enrichment factors and fractional solubility measurements indicate the presence of a significant anthropogenic component in the aerosols collected furthest from the North African dust plume for both Zn and Cu. The mean δ⁶⁵Cu_{NIST SRM 976} for the fully digested aerosols is +0.07 ± 0.39 ‰ (n = 9, 2 SD), which is indistinguishable from the lithogenic value, and implies that Cu isotopes are not an effective tracer of aerosol sources in this region. The mean δ⁶⁶Zn_JMC-Lyon value for the aerosols that underwent a total digestion is +0.17 ± 0.22 ‰ (n = 11, 2 SD). The aerosols leached with ammonium acetate have similar Zn isotope compositions, with a mean of +0.15 ± 0.16 ‰ (n = 7, 2 SD). The aerosols were collected in a region with prevalent mineral dust but, despite this, exhibit isotopically lighter Zn than lithogenic Zn with δ⁶⁶Zn ≈ +0.3 ‰. When coupled with the previously published Pb isotope data, the aerosols exhibit coupled Zn-Pb isotope systematics that are indicative of mixing between mineral dust (δ⁶⁶Zn = +0.28 ‰ and ²⁰⁶Pb/²⁰⁷Pb = 1.205) and anthropogenic emissions (δ⁶⁶Zn = −0.22 ‰ and ²⁰⁶Pb/²⁰⁷Pb = 1.129). This demonstrates the potential of Zn isotopes to trace atmospheric Zn inputs from anthropogenic sources to the surface ocean.

人为活动显着增加了对海洋的大气金属输入，这对海洋生态系统具有潜在的重要影响。本研究评估了 Zn 和 Cu 同位素组成的潜力，以区分这些金属对表层海洋的自然和人为大气输入。为此，研究了 GEOTRACES GA06 巡航从东热带大西洋收集的气溶胶中 Zn 和 Cu 的同位素组成。富集因子和分数溶解度测量表明，在距离北非尘埃羽流最远收集的锌和铜的气溶胶中存在显着的人为成分。完全消化气溶胶的平均 δ ⁶⁵ Cu _{NIST SRM 976}为 +0.07 ± 0.39 ‰ ( n = 9, 2 SD)，这与成岩值无法区分，表明铜同位素不是该地区气溶胶源的有效示踪剂。经完全消化的气溶胶的平均 δ ⁶⁶ Zn _JMC-Lyon值为 +0.17 ± 0.22 ‰ ( n  = 11, 2 SD)。醋酸铵浸出的气溶胶具有相似的 Zn 同位素组成，平均值为 +0.15 ± 0.16 ‰ ( n  = 7, 2 SD)。气溶胶是在一个富含矿物尘埃的地区收集的，但尽管如此，它的 Zn 同位素比成岩 Zn 轻，δ ⁶⁶锌≈+0.3‰。当与先前公布的 Pb 同位素数据相结合时，气溶胶表现出耦合的 Zn-Pb 同位素系统，表明矿物尘埃（δ ⁶⁶ Zn = +0.28 ‰ 和²⁰⁶ Pb/ ²⁰⁷ Pb = 1.205）和人为排放（δ ⁶⁶ Zn = -0.22 ‰ 和²⁰⁶ Pb/ ²⁰⁷ Pb = 1.129)。这证明了 Zn 同位素在追踪大气 Zn 输入从人为来源到表层海洋的潜力。