Stratigraphy of sea-ice cores collected in the Eurasian basin during CAATEX 2019 cruise

The physical properties of sea ice, including salinity, sea ice temperature, and sea ice texture as well as isotopic composition (oxygen and hydrogen) were analyzed from samples collected on the CAATEX 2019 expedition to the central Arctic Ocean (between North Pole and Svalbard) in late summer 2019. In addition, isotope samples were collected from precipitation, melt ponds, and under-ice seawater. Data was collected to understand the formation mechanisms of sea ice in the area. Ice cores were collected with an ice corer, and measurements (temperature) were directly carried out from ice cores after retrieval. From an additional ice core, samples (salinity and isotopes) were collected and melted onboard. Salinity of samples was measured onboard using a conductivity probe, while samples for isotopic composition were placed in sample bottles and measured at the FARLAB (University of Bergen) after the expedition . A complete ice core was brought back for texture analysis of the sea ice and processed at the freezer lab at the Norwegian Polar Institute. Texture was examined by first slicing ice samples very thin by use of a microtome. These thin ice slices were observed in polarized light that reveals the crystal structure of the ice. This data includes the photographs taken of the ice cores in natural light and in polarized light.本数据集针对2019年夏末于北冰洋中部（北极点与斯瓦尔巴群岛之间）开展的CAATEX 2019科考航次所采集的海冰样本，分析了其盐度、海冰温度、海冰纹理以及同位素组成（氧与氢）。此外，研究团队还从降水、融水池以及冰下海水采集了同位素样本，本次数据采集工作旨在阐明该区域海冰的形成机制。科考人员使用冰钻采集冰芯，回收后直接对冰芯开展温度测量；另有一根额外冰芯，采集其样本用于盐度与同位素分析，并在船载环境下完成融样。样本盐度通过船载电导探针现场测定；用于同位素组成分析的样本则被装入样品瓶，待航次结束后于卑尔根大学FARLAB实验室完成检测。一整根完整冰芯被带回，用于海冰纹理分析，并于挪威极地研究所的低温实验室完成处理：先使用切片机将冰样切为极薄切片，随后通过偏振光观察以揭示冰的晶体结构。本数据集包含自然光下与偏振光下拍摄的冰芯照片。