Antarctic ice sheet topography, cavity geometry, and global bathymetry (RTopo 1.0.5-beta)

Sub-ice shelf circulation and freezing/melting rates in ocean general circulation models depend critically on an accurate and consistent representation of cavity geometry. Existing global or pan-Antarctic data sets have turned out to contain various inconsistencies and inaccuracies. The goal of this work is to compile independent regional fields into a global data set. We use the S-2004 global 1-minute bathymetry as the backbone and add an improved version of the BEDMAP topography for an area that roughly coincides with the Antarctic continental shelf. Locations of the merging line have been carefully adjusted in order to get the best out of each data set. High-resolution gridded data for upper and lower ice surface topography and cavity geometry of the Amery, Fimbul, Filchner-Ronne, Larsen C and George VI Ice Shelves, and for Pine Island Glacier have been carefully merged into the ambient ice and ocean topographies. Multibeam survey data for bathymetry in the former Larsen B cavity and the southeastern Bellingshausen Sea have been obtained from the data centers of Alfred Wegener Institute (AWI), British Antarctic Survey (BAS) and Lamont-Doherty Earth Observatory (LDEO), gridded, and again carefully merged into the existing bathymetry map. The global 1-minute dataset (RTopo-1 Version 1.0.5) has been split into two NetCDF files. The first contains digital maps for global bedrock topography, ice bottom topography, and surface elevation. The second contains the auxiliary maps for data sources and the surface type mask. A regional subset that covers all variables for the region south of 50 deg S is also available in NetCDF format. Datasets for the locations of grounding and coast lines are provided in ASCII format.海洋环流模式中的冰架下环流与冻结/消融速率，高度依赖于冰腔几何形态的精准且一致的表征。现有全球或泛南极数据集存在各类不一致性与精度误差。本研究旨在将独立的区域场数据整合为一套全球数据集。本研究以S-2004全球1分钟测深地形作为核心基底，并针对大致与南极大陆架重合的区域，补充了改进版的BEDMAP地形数据。为充分发挥各数据集的优势，研究人员已对拼接边界的位置进行了精细调校。针对埃默里冰架、芬布尔冰架、菲尔希纳-龙尼冰架、拉森C冰架、乔治六世冰架以及派恩岛冰川的冰上下表面地形与冰腔几何形态的高分辨率格点数据，已被精细整合至周边冰与海洋地形数据集当中。针对原拉森B冰架冰腔与别林斯高晋海东南部的测深多波束勘测数据，已从阿尔弗雷德·魏格纳研究所（Alfred Wegener Institute, AWI）、英国南极调查局（British Antarctic Survey, BAS）以及拉蒙特-多赫蒂地球观测站（Lamont-Doherty Earth Observatory, LDEO）的数据中心获取，经格点化处理后，再次被精细整合至现有测深地形地图中。本全球1分钟数据集（RTopo-1 版本1.0.5）已被拆分为两个NetCDF格式文件。第一个文件包含全球基岩地形、冰下地形与地表高程的数字地图。第二个文件则包含数据源与地表类型掩码的辅助地图。针对南纬50度以南区域的全变量区域子集，同样以NetCDF格式提供。冰架接地线与海岸线的相关数据集，以ASCII格式提供。