Concentrations of dissolved thorium and protactinium isotopes (Th-232, Th-230, Pa-231) in seawater, sea ice, and melt ponds collected during the U.S. GEOTRACES Arctic cruise (HLY1502, GN01) on USCGC Healy from August to October 2015

<p>This dataset contains concentrations of dissolved thorium and protactinium isotopes (Th-232, Th-230, Pa-231) in seawater, sea ice, and melt ponds collected during the U.S. GEOTRACES Arctic cruise (HLY1502, GN01) on USCGC Healy from August to October 2015. This is compiled data produced by two laboratories with the following associations: Lamont-Doherty Earth Observatory of Columbia University (LDEO) and the University of Minnesota (UMN). All data have been deemed intercalibrated by the International GEOTRACES Standards and Intercalibration (S&amp;I) Committee.</p> <p><strong>Naming Conventions:</strong><br /> Parameter names in the form such as \"Th_232_D_CONC_BOTTLE\" are adopted based on a recommendation from the GEOTRACES community (<a href=\"https://www.geotraces.org/parameter-naming-conventions/\" target=\"_blank\">https://www.geotraces.org/parameter-naming-conventions/</a>).</p> <p>A GEOTRACES sample number (Sample_ID) appended with an \"A\" denotes the archive sample collected during the same cast and at the same depth as the sample that was originally analyzed.</p> <p>\"Dissolved\" (D) here refers to that which passed through stacked 0.8/0.45 µm Acropak™ 500 filter capsules sampled from conventional Niskin bottles on a CTD rosette (BOTTLE; NIS and GSNIS). This is true for all dissolved samples except for a select number that were collected using GO-FLO bottles on a CTD rosette (BOTTLE; GF), a pump from a small boat (BOAT_PUMP; SMBT), a pump through sea ice into seawater (SUBICE_PUMP), a trace metal clean ice corer (CORER), and a pump into a melt pond (MELTPOND_PUMP). Sampling system is indicated by the parameter name, and in some cases by Bottle_ID. For Bottle_ID, NIS represents Niskin bottles sampled from the 12-place 30 liter ODF rosette, GSNIS represents Niskin bottles sampled from the 36-place 10 liter GO-SHIP rosette, GF represents GO-FLO bottles sampled from the 24-place 12 liter GTC clean carousel, and SMBT represents surface (1 m) seawater samples collected from a small boat upstream of the ship using a battery-powered pump and Teflon-lined PVC tubing. SUBICE_PUMP represents seawater samples collected from under the ice (at approximately 1, 5, and 20 m) with the same pumping system used for BOAT_PUMP, MELTPOND_PUMP represents melt pond water samples that were collected using a battery-powered peristaltic pump and silicone tubing, and CORER represents sea ice samples that were collected using a trace metal clean ice corer. Bulk sea ice (CORER) samples were collected as ice cores about 1 m in length and melted overnight in LDPE melting chambers before they were subsampled into 5 liter cubitainers. BOAT_PUMP, SUBICE_PUMP, and MELTPOND_PUMP samples were each stored in 25 liter carboys during sample collection and then subsampled into 5 liter cubitainers aboard the ship. GF (BOTTLE), BOAT_PUMP, MELTPOND_PUMP, and CORER samples were passed through a 0.2 µm Acropak™ 200 filter capsule, unlike NIS (BOTTLE), GSNIS (BOTTLE), and SUBICE_PUMP samples, which were passed through stacked 0.8/0.45 µm Acropak™ 500 filter capsules. All seawater, sea ice, and melt pond samples were weighed directly in the on-shore laboratory to determine sample size, taking into account acid added at sea.</p> <p><strong>Units of Measurement:</strong><br /> Radionuclide concentrations are given as micro-Becquerel (10e-6 Bq, µBq or micro-Bq) per kilogram water for Th-230 and Pa-231, and picomole (10e-12 mol, pmol) per kilogram water for Th-232. A Becquerel is the SI unit for radioactivity and is defined as 1 disintegration per second. These units are recommended by the GEOTRACES community.</p> <p><strong>Results Publications:</strong><br /> These data have been published in the following:<br /> Charette et al., 2020 – Dissolved Th-232 concentrations in upper ocean waters (Th_232_D_CONC_BOTTLE_dan73c)</p>本数据集包含2015年8月至10月期间，在美国海岸警卫队希利号（USCGC Healy）执行美国GEOTRACES北极科考航次（HLY1502、GN01）期间采集的海水、海冰及融池样品中的溶解态钍与镤同位素（Th-232、Th-230、Pa-231）浓度数据。本数据集为两家合作实验室的整合成果，分别是哥伦比亚大学拉蒙特-多尔蒂地球观测站（Lamont-Doherty Earth Observatory of Columbia University, LDEO）与明尼苏达大学（University of Minnesota, UMN）。所有数据均通过国际GEOTRACES标准与互校准（Standards and Intercalibration, S&I）委员会的互校准验证。 **命名规范：** 参数命名采用如"Th_232_D_CONC_BOTTLE"的格式，该格式遵循GEOTRACES社区的推荐规范（<a href="https://www.geotraces.org/parameter-naming-conventions/" target="_blank">https://www.geotraces.org/parameter-naming-conventions/</a>）。 带有后缀"A"的GEOTRACES样品编号（Sample_ID），代表与原始分析样品同站位、同深度采集的存档样品。 此处的"溶解态（D）"指通过堆叠式0.8/0.45 µm Acropak™ 500过滤胶囊的组分，该过滤装置配套CTD采水器架上的常规尼斯金（Niskin）采水瓶（BOTTLE；NIS与GSNIS）使用。除少数特定样品外，所有溶解态样品均采用此处理方式，包括：CTD采水器架上的GO-FLO采水瓶（BOTTLE；GF）采集的样品、小型船载泵采（BOAT_PUMP；SMBT）样品、穿海冰泵入海水的（SUBICE_PUMP）样品、痕量金属洁净冰钻（CORER）采集的样品，以及泵入融池的（MELTPOND_PUMP）样品。 采样系统由参数名称标识，部分情况下也可通过Bottle_ID确认。关于Bottle_ID：NIS代表从12位30升ODF采水器架采集的尼斯金采水瓶样品；GSNIS代表从36位10升GO-SHIP采水器架采集的尼斯金采水瓶样品；GF代表从24位12升GTC洁净旋转采样架采集的GO-FLO采水瓶样品；SMBT代表使用电池驱动泵与聚四氟乙烯内衬聚氯乙烯管，在船舶上游1米处的小型船上采集的表层海水样品。SUBICE_PUMP代表使用与BOAT_PUMP同款泵系统，从冰下（约1米、5米及20米深度）采集的海水样品；MELTPOND_PUMP代表使用电池驱动蠕动泵与硅树脂管采集的融池水样品；CORER代表使用痕量金属洁净冰钻采集的海冰样品。 批量海冰（CORER）样品以约1米长的冰芯形式采集，在低密度聚乙烯（LDPE）融样舱中过夜融化后，分装至5升立方样品容器中。BOAT_PUMP、SUBICE_PUMP及MELTPOND_PUMP样品在采集过程中均储存在25升大桶中，随后在船上分装至5升立方样品容器。 与NIS（BOTTLE）、GSNIS（BOTTLE）及SUBICE_PUMP样品（采用堆叠式0.8/0.45 µm Acropak™ 500过滤胶囊过滤）不同，GF（BOTTLE）、BOAT_PUMP、MELTPOND_PUMP及CORER样品均通过0.2 µm Acropak™ 200过滤胶囊过滤。所有海水、海冰及融池样品均在陆上实验室直接称重以确定样品体积，同时考虑到海上添加的酸液体积。 **测量单位：** 放射性核素浓度单位遵循GEOTRACES社区推荐标准：Th-230与Pa-231的浓度以每千克水中的微贝可（10⁻⁶ Bq，µBq或微Bq）表示，Th-232的浓度以每千克水中的皮摩尔（10⁻¹² mol，pmol）表示。贝可（Becquerel）是放射性活度的国际单位制（SI）单位，定义为每秒发生一次核衰变。 **成果发表：** 本数据集相关成果已发表于： Charette等人，2020年——上层海水中溶解态Th-232浓度（Th_232_D_CONC_BOTTLE_dan73c）