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。本数据集为社区共建项目，旨在发布易用的原位观测数据，以助力地表质量平衡建模与遥感研究工作。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，请同时引用数据引用字段中列明的原始数据提供者，以及本数据集本身。本数据集包含两大冰盖、冰帽以及海冰积雪的雪密度测量数据，不包含陆地季节性积雪的测量结果。数据集共包含超过220万个不同深度的密度点测量值。所用测量方法包括雪坑与冰芯样品中使用的不同规格密度切割机（通常体积为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、比重瓶法、光学声波成像（OPTV）钻孔测井，以及密度-电导率混合介电常数法（DECOMP）。观测数据中约72%来自格陵兰岛的冰芯或雪坑测量，南极数据占雪密度子数据集的约28%，且主要来源于冰芯测量。密度测量的深度采用两种方式记录：起止深度法，或中点深度法。数据集字段包括测量日期、纬度、经度、起始深度、终止深度、中点深度、密度值、误差值、海拔高度、测量方法及相关引用信息。