Samples for organic copper (Cu)-binding ligand characterization were collected along the 2013 U.S. GEOTRACES Pacific (GP16) cruise transect from Peru to Tahiti. Full depth profiles of Cu speciation were collected across a dynamic range in oceanographic conditions including a highly productive coastal region, an oxygen deficient zone, a high nutrient low chlorophyll (HNLC) region, an oligotrophic region and a hydrothermal vent plume. Surface waters from Peru to Tahiti exhibited elevated dissolved Cu and ligand concentrations near Peru and then decreased in concentration (< 1 nM) offshore toward the oligotrophic waters. There was also an apparent shelf sediment source of strong Cu-binding ligands near the coast of Peru. Throughout most of the transect dissolved Cu and ligand concentrations were lower in the upper waters and increased with depth, with the highest concentrations near the ocean bottom. The hydrothermal vent sampled during the cruise did not seem to be a source for dissolved Cu but there was a slight elevation of Cu-binding ligands at the vent site. Similar vertical patterns in Cu-binding ligands were seen in both the GP16 dataset and the North Atlantic GEOTRACES (GA03) cruise, with notable differences in deep waters of the Pacific. The older water masses of the Pacific were highlighted by higher concentrations of dissolved Cu, Cu-binding ligands, and the free Cu ion (Cu²⁺) relative to the deep Atlantic. Excess Cu ligands in both GP16 and GA03 point to a possible fraction of Cu accumulating in the deep Pacific that is inert to ligand exchange, suggesting older waters might contain a high fraction of unreactive Cu.

从秘鲁到塔希提岛的2013 US GEOTRACES太平洋（GP16）巡航剖面收集了有机铜（Cu）结合配体表征的样品。在包括高产沿海地区，缺氧区，高营养低叶绿素（HNLC）区，贫营养区和热液喷口羽流在内的海洋条件下，动态范围内收集了全铜形态的深度剖面。从秘鲁到塔希提岛的地表水在秘鲁附近表现出较高的溶解铜和配体浓度，然后向贫营养水域的浓度降低（<1 nM）。在秘鲁海岸附近也有明显的由强Cu结合配体构成的架子沉积物来源。在整个样带中，大部分溶解态的铜和配体浓度在上层水域较低，并随深度增加，在海底附近浓度最高。航行期间采样的热液喷口似乎不是溶解的铜的来源，但喷口处的铜结合配体略有升高。在GP16数据集和北大西洋GEOTRACES（GA03）航行中都发现了类似的垂直于铜结合配体的模式，但太平洋深水区存在明显差异。较高浓度的溶解铜，与铜结合的配体和游离铜离子（铜 在GP16数据集和北大西洋GEOTRACES（GA03）航行中都发现了类似的垂直于铜结合配体的模式，但太平洋深水区存在明显差异。较高浓度的溶解铜，与铜结合的配体和游离铜离子（铜 在GP16数据集和北大西洋GEOTRACES（GA03）航行中都发现了类似的垂直于铜结合配体的模式，但太平洋深水区存在明显差异。较高浓度的溶解铜，与铜结合的配体和游离铜离子（铜²⁺）相对于深大西洋。GP16和GA03中过量的铜配体表明在深太平洋中积累的铜可能对配体交换呈惰性，这表明较老的水域可能含有大量未反应的铜。