Tracing natural and anthropogenic sources of aerosols to the Atlantic Ocean using Zn and Cu isotopes

Anthropogenic activities have significantly enhanced atmospheric metal inputs to the ocean, which has potentially important consequences for marine ecosystems. This study assesses potential of Zn and Cu isotope compositions distinguish between natural anthropogenic these metals surface ocean. To this end, isotopic in aerosols collected from eastern tropical Atlantic Ocean on GEOTRACES GA06 cruise are examined. Enrichment factors fractional solubility measurements indicate presence a significant component furthest North African dust plume both Cu. The mean δ65CuNIST SRM 976 fully digested is +0.07 ± 0.39 ‰ (n = 9, 2 SD), indistinguishable lithogenic value, implies that isotopes not an effective tracer aerosol sources region. δ66ZnJMC-Lyon value underwent total digestion +0.17 0.22 11, SD). leached with ammonium acetate similar compositions, +0.15 0.16 7, were region prevalent mineral but, despite this, exhibit isotopically lighter than δ66Zn ≈ +0.3 ‰. When coupled previously published Pb data, Zn-Pb systematics indicative mixing (δ66Zn +0.28 206Pb/207Pb 1.205) emissions −0.22 1.129). demonstrates trace