Surface Mass Balance and Snow Depth on Sea Ice Working Group (SUMup) snow density subdataset, Greenland and Antartica, 1950-2018

This dataset includes snow density measurements from both hemispheres. This dataset is a community effort to distribute easy to use in-situ data to improve surface mass balance modeling and remote sensing efforts. This dataset is a compilation of work from many individual researchers. When using this dataset please cite both the individual researchers who provided the data as listed in the Citation field as well as this dataset. This dataset includes snow density measurements over both ice sheets, ice caps and snow on sea ice. It excludes seasonal snow on land measurements. The dataset contains over 2,200,000 point measurements of density at different depths. The measurement methods include different sized density cutters (generally from 100 - 1000 cc) used in snow pits, ice core sections, neutron-density methods, X-ray microfocus computer tomography, Gamma-ray attenuation, pycnometers, optical televiewer (OPTV) borehole logging, and Density-and-conductivity mixed permittivity (DECOMP).The majority of the observations (~72%) come from Greenland ice cores or snow pits. Antarctic data comprises ~28% of the snow density subdataset and is predominately from ice cores. The depth of the density measurements are recorded using two different methods, either the top and bottom depth or a midpoint depth. Fields of the data include the date taken, latitude, longitude, start depth, stop depth, midpoint depth, density, error, elevation, method, and associated citation.

本数据集涵盖南北半球的雪密度测量数据。本数据集由社区共建，旨在发布易于使用的原位观测数据，以助力地表质量平衡模拟与遥感研究工作。本数据集整合了众多独立研究者的研究成果。使用本数据集时，请同时引用数据提供方（详见引用字段中列出的研究者）与本数据集本身。本数据集包含两大冰盖、冰帽以及海冰上积雪的雪密度测量数据，不含陆地季节性积雪的测量结果。本数据集包含超过220万个不同深度的密度点位测量数据。所用测量方法涵盖雪坑、冰芯切片中使用的不同规格密度切割器（通常容积为100~1000 cc）、中子密度法、X射线微焦点计算机断层扫描、伽马射线衰减法、密度瓶法、光学成像测井仪（Optical Televiewer, OPTV）钻孔测井，以及密度-电导率混合介电常数法（Density-and-conductivity mixed permittivity, DECOMP）。绝大多数观测数据（约72%）来自格陵兰冰芯或雪坑；南极数据占本雪密度子数据集的约28%，且主要源自冰芯。密度测量的深度采用两种方式记录：顶部深度与底部深度，或中点深度。数据集字段包括采集日期、纬度、经度、起始深度、终止深度、中点深度、密度值、误差、海拔、测量方法及相关引用信息。