Dissolved gallium (Ga) from the US GEOTRACES GP17-OCE cruise on R/V Roger Revelle (RR2214) in the South Pacific and Southern Oceans from December 2022 to January 2023

Dissolved gallium (Ga) was determined in association with a US GEOTRACES cruise (GP17-OCE/RR2214) in the South Pacific and Southern Ocean. The cruise sampled formation regions for globally distributed water masses, the return flow of Pacific Deep Water into the Southern Ocean, hydrothermally influenced waters, margin waters, and a gradient of low to high productivity with varying limiting nutrients. The cruise track investigates circulation through the Antarctic Circumpolar Current (ACC) and formation of intermediate waters important for upper ocean nutrient supply. The overall circulation/productivity/export/recycling trap of this region also affects how oceanic element-element relationships develop. For Ga, its distribution can provide insight into dust delivery, which recent work has suggested may be higher than previously thought in the study area. Ga's limited reactivity also allows its distribution to be used for water mass deconvolution, which could be usefully applied to the ACC and intermediate water formation regions. Data include dissolved Ga concentrations from bottle and towed fish samples.

本数据集针对南太平洋与南大洋的美国GEOTRACES航次（GP17-OCE/RR2214），完成了溶解态镓（dissolved gallium, Ga）的测定工作。该航次的采样覆盖了全球分布水团的形成区域、太平洋深层水回流至南大洋的通道、受热液活动影响的海域、大陆边缘海域，以及营养盐限制因子各异、生产力水平呈低至高梯度变化的海域。航次轨迹覆盖了南极绕极流（Antarctic Circumpolar Current, ACC）区域的环流过程，以及对上层海洋营养盐供给至关重要的中层水团形成过程。该区域整体的环流-生产力-输出-再循环汇系统，同样会影响海洋中元素间关联关系的演化。就镓而言，其分布特征可揭示大气粉尘沉降情况——近期研究表明，本研究区域的粉尘沉降量或高于此前的预估。镓有限的反应活性，使其分布特征可用于水团解构分析，该方法可有效应用于南极绕极流及中层水团形成区域。本数据集包含采自采水瓶与拖曳式鱼形采水器（towed fish）样品的溶解态镓浓度数据。