Southeast Greenland Bed Elevation - v2

We employ NASA's Operation IceBridge (OIB) high‐resolution airborne gravity from 2016, NASA's Ocean Melting Greenland (OMG) bathymetry from 2015, ice thickness from Operation IceBridge (OIB) from 2010‐2015, and BedMachine v3 to analyze 20 major southeast Greenland glaciers. The results reveal glacial fjords several hundreds of meters deeper than previously thought; the full extent of the marine‐based portions of the glaciers; deep troughs enabling warm, salty Atlantic Water (AW) to reach the glacier fronts and melt them from below; and few shallow sills that limit the access of AW. The new oceanographic and topographic data help to fully resolve the complex pattern of historical ice front positions from the 1930s to 2017: glaciers exposed to AW and resting on retrograde beds have retreated rapidly, while glaciers perched on shallow sills or standing in colder waters or with major sills in the fjords have remained stable. Please cite the following paper when using this dataset: Millan R., E. Rignot, J. Mouginot, M. Wood, A.A Bjørk, and M. Morlighem (2018), Vulnerability of Southeast Greenland glaciers to warm Atlantic Water from Operation IceBridge and Ocean Melting Greenland data, Geophys. Res. Lett., 45, doi:10.1002/2017GL076561. Projection informations can be found below: Size is 2760, 4044 Coordinate System is: PROJCS["WGS 84 / NSIDC Sea Ice Polar Stereographic North", GEOGCS["WGS 84", DATUM["WGS_1984", SPHEROID["WGS 84",6378137,298.257223563, PROJECTION["Polar_Stereographic"], PARAMETER["latitude_of_origin",70], PARAMETER["central_meridian",-45], PARAMETER["scale_factor",1], PARAMETER["false_easting",0], PARAMETER["false_northing",0], AUTHORITY["EPSG","3413"]] Origin = (-109288.637000000002445,-2616698.799999999813735) Pixel Size = (150.000000000000000,-150.000000000000000) Metadata: AREA_OR_POINT=Area Image Structure Metadata: INTERLEAVE=BAND Corner Coordinates: Upper Left ( -109288.637,-2616698.800) ( 47d23'29.82"W, 66d 9'34.51"N) Lower Left ( -109288.637,-3223298.800) ( 46d56'30.90"W, 60d50'52.57"N) Upper Right ( 304711.363,-2616698.800) ( 38d21'28.41"W, 66d 1'23.84"N) Lower Right ( 304711.363,-3223298.800) ( 39d35'58.74"W, 60d44'22.03"N) Center ( 97711.363,-2919998.800) ( 43d 5' 0.37"W, 63d29'36.85"N)

本研究采用美国国家航空航天局（National Aeronautics and Space Administration, NASA）2016年的冰桥行动（Operation IceBridge, OIB）高分辨率航空重力数据、2015年的格陵兰海洋融化项目（Ocean Melting Greenland, OMG）海底地形数据、2010-2015年冰桥行动（OIB）的冰厚数据，以及BedMachine v3数据集，对格陵兰东南部20处主要冰川开展分析。

研究结果表明，本次研究涉及的冰川峡湾实际深度较此前认知深达数百米；明确了冰川海洋基底区域的完整分布范围；识别出深层槽谷结构，该结构可使温暖咸化的大西洋水（Atlantic Water, AW）抵达冰川前端并从底部侵蚀冰川；同时仅存在少量可限制大西洋水侵入的浅海槛。

本次更新的海洋学与地形数据，可完整还原1930年至2017年期间冰川前端位置的复杂变化规律：暴露于大西洋水且坐落于逆向基床上的冰川发生了快速退缩，而依托浅海槛、处于冷水环境或峡湾内存在大型海槛的冰川则保持了相对稳定。

使用本数据集时，请引用以下文献：Millan R.、Rignot E.、Mouginot J.、Wood M.、Bjørk A.A.与Morlighem M.（2018），《格陵兰东南部冰川对暖化大西洋水的脆弱性——基于冰桥行动与格陵兰海洋融化项目数据》，《地球物理研究通讯》（Geophys. Res. Lett.），第45卷，DOI:10.1002/2017GL076561。

投影信息如下：
数据集尺寸：2760×4044
坐标系：PROJCS["WGS 84 / NSIDC海冰北极极方位立体投影（WGS 84 / NSIDC Sea Ice Polar Stereographic North）", GEOGCS["WGS 84", DATUM["WGS_1984", SPHEROID["WGS 84",6378137,298.257223563], PROJECTION["极方位立体投影（Polar_Stereographic）"], PARAMETER["原点纬度",70], PARAMETER["中央经线",-45], PARAMETER["比例因子",1], PARAMETER["假东向偏移",0], PARAMETER["假北向偏移",0], AUTHORITY["EPSG","3413"]]]
原点坐标：(-109288.637000000002445, -2616698.799999999813735)
像素分辨率：(150.000000000000000, -150.000000000000000)
元数据：
AREA_OR_POINT=Area
图像结构元数据：INTERLEAVE=BAND
角点坐标：
左上角：(-109288.637, -2616698.800) （西经47°23′29.82″，北纬66°9′34.51″）
左下角：(-109288.637, -3223298.800) （西经46°56′30.90″，北纬60°50′52.57″）
右上角：(304711.363, -2616698.800) （西经38°21′28.41″，北纬66°1′23.84″）
右下角：(304711.363, -3223298.800) （西经39°35′58.74″，北纬60°44′22.03″）
中心点：(97711.363, -2919998.800) （西经43°5′0.37″，北纬63°29′36.85″）