Metadata file presenting the stable isotope toolbox used to describe the biogeochemical system functioning during the SIPEX II voyage of the Aurora Australis, 2012

Overview of the project and objectives:

To investigate whether the Nitrogen - Silicon - Carbon biogeochemical system functions in the Antarctic Marginal Ice Zone and shows spatial variability possibly induced by varying availability of Fe and other parameters in the region. This toolbox is part of project 4051 - samples were taken (1) on the same sea-ice site or very close than the one used for Trace Metal sampling; (2) via Trace Metal Rosette TMR; (3) via Conductivity Temperature and Depth CTD Rosette. It is also part of project 4073 since some intercalibration studies were conducted in collaboration with the primary production team.

Three main tools were used which can be either independently or intricately studied. For this reason the complete set of sampling done for this stable isotope toolbox is summarized in one excel file which is duplicated and attached to three child metadata records. Same reasoning for raw data acquired on boar and on field information.

This parent metadata record has thus three child metadata records. Each of the child metadata files explain individually the different approaches which were treated together by the same team to resolve the main question of sea-ice biogeochemical system functioning via the use of stable isotope ratio tools. The details of each are in the respective metadata records.

The data are attached to this metadata record.

METADATA FILES are:

- 13C, 15N, 30Si in-situ incubation experiments during SIPEX 2
- Nitrogen and oxygen isotopic composition of nitrate during SIPEX 2
- Delta13C signal of brassicasterol and cholesterol in the Antarctic Sea-ice / Is there particulate barium in sea-ice?

项目与目标概述：
本研究旨在探究南极边缘冰区的氮-硅-碳生物地球化学系统是否存在运作机制，并呈现可能由该区域铁（Fe）及其他参数的可用性差异所诱导的空间异质性。本工具箱隶属于项目4051——采样工作通过三种方式完成：(1) 在与痕量金属采样相同或极邻近的海冰点位开展；(2) 借助痕量金属采水器（Trace Metal Rosette, TMR）实施；(3) 通过温盐深（Conductivity Temperature and Depth, CTD）采水器完成。同时，本工具箱亦隶属于项目4073，因部分互校研究系与初级生产力研究团队合作开展。

本研究采用三类核心工具，可独立开展分析亦可进行复杂联用。为此，本稳定同位素工具箱的全套采样数据汇总于一份Excel文件中，该文件已复制并附至三份子元数据记录中。针对船载原始数据与野外采集信息的处理逻辑亦与此一致。

因此，本元数据主记录关联三份子元数据记录。每份子元数据文件将分别阐释同一团队为解决核心科学问题所采用的不同研究路径——该问题为：通过稳定同位素比值分析手段解析海冰生物地球化学系统的运作机制。各工具的详细说明详见对应元数据记录。

本元数据记录已附相关数据。

元数据文件包括：
- SIPEX 2期间开展的13C、15N、30Si原位培养实验
- SIPEX 2期间采集的硝酸盐氮、氧同位素组成数据
- 南极海冰中菜籽甾醇（brassicasterol）与胆固醇的δ13C信号 / 南极海冰中是否存在颗粒态钡？