Ice thickness and bed elevation of the Patagonian Icefields

We combine airborne gravity data collected in 2012 and 2016, with WISE and CECs radar sounder data from 2014 and 2015 to map bed elevation and ice thickness accross the Northern and Southern Patagonian Icefields. We perform a three dimensional inversion of the gravity field constrained by radar-derived thickness, ice boundary, and fjord bathymetry to infer bed elevation at 500-m spacing, with a precision of about 50 m. The enclosed netCDF contains the following fields: - X: x UTM coordinate (meters) -Y: y UTM coordinate (meters) -bed: bedrock elevation (meters) -misfit: Misfit after inversion (calculated minus observed gravity) -misfitm: Converted misfit using a conversion factor of 5.8 mGal per 100m -Source: Data source, 0=bathymetry , 1=gravity, 2=radar depth sounder -Fulthick: Comprehensive Ice thickness calculated using gravity inversion inside the survey domain and Carrivick 2016 modified outside. The projection is given as: "PROJCS[\"WGS 84 / UTM zone 18S\",GEOGCS[\"WGS 84\",DATUM[\"WGS_1984\",SPHEROID[\"WGS 84\",6378137,298.257223563,AUTHORITY[\"EPSG\",\"7030\"]],AUTHORITY[\"EPSG\",\"6326\"]],PRIMEM[\"Greenwich\",0,AUTHORITY[\"EPSG\",\"8901\"]],UNIT[\"degree\",0.0174532925199433,AUTHORITY[\"EPSG\",\"9122\"]],AUTHORITY[\"EPSG\",\"4326\"]],PROJECTION[\"Transverse_Mercator\"],PARAMETER[\"latitude_of_origin\",0],PARAMETER[\"central_meridian\",-75],PARAMETER[\"scale_factor\",0.9996],PARAMETER[\"false_easting\",500000],PARAMETER[\"false_northing\",10000000],UNIT[\"metre\",1,AUTHORITY[\"EPSG\",\"9001\"]],AXIS[\"Easting\",EAST],AXIS[\"Northing\",NORTH],AUTHORITY[\"EPSG\",\"32718\"]]" ;本研究整合了2012年与2016年采集的航空重力数据，以及2014年、2015年获取的WISE与CECs雷达测深数据，用于绘制巴塔哥尼亚南北冰原的床面高程与冰厚分布。我们以雷达反演得到的冰厚、冰体边界以及峡湾水深作为约束条件，对重力场开展三维反演，以500米的空间分辨率推算床面高程，推算精度约为50米。随附的网络通用数据格式（netCDF）文件包含以下字段： - X：x轴通用横轴墨卡托（UTM）坐标（单位：米） - Y：y轴通用横轴墨卡托（UTM）坐标（单位：米） - bed：基岩高程（单位：米） - misfit：反演残差（计算重力与观测重力的差值） - misfitm：转换残差（以每100米5.8毫伽（mGal）为转换系数得到的残差值） - Source：数据源，其中0代表水深数据，1代表重力数据，2代表雷达测深数据 - Fulthick：综合冰厚：在研究区域内通过重力反演计算得到，研究区域外则采用经Carrivick团队2016年研究修正的冰厚数据。该数据采用的投影坐标系为："PROJCS["WGS 84 / UTM zone 18S",GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",-75],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",10000000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","32718"]]"