6071926f-32e0-4681-a50d-aab08f42c08a eng utf8 dataset dataset NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom polardatacentre@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact 2018-02-02 ISO 19115 Geographic Information - Metadata ISO 19115:2003(E) European Petroleum Survey Group (EPSG) Geodetic Parameter Registry 2008-11-12 publication European Petroleum Survey Group EPSGadministrator@iogp.org https://www.epsg-registry.org/ EPSG Geodetic Parameter Dataset The EPSG Geodetic Parameter Dataset is a structured dataset of Coordinate Reference Systems and Coordinate Transformations, accessible through this online registry. information publisher urn:ogc:def:crs:EPSG::3031 6.18.3 Subglacial bed roughness of Greenland, provided using two independent metrics 2018-02-02 creation 2018-02-02 revision 2018-02-02 publication 2018-02-02 released None https://doi.org/10.5285/6071926f-32e0-4681-a50d-aab08f42c08a doi GB/NERC/BAS/PDC/01060 https://data.bas.ac.uk/ NE/M000869/1 award Please cite this item as: Cooper, M., & Jordan, T. (2018). Subglacial bed roughness of Greenland, provided using two independent metrics (Version None) [Data set]. Polar Data Centre, Natural Environment Research Council, UK. https://doi.org/10.5285/6071926f-32e0-4681-a50d-aab08f42c08a These two files (.csv) provide independent methods of quantifying subglacial roughness in Greenland, both calculated from radio-echo sounding (or ice penetrating radar) data collected by the Operation Ice Bridge programme using CReSIS instrumentation. They are an output of the Basal Properties of Greenland (BPOG) project (http://bpog.blogs.ilrt.org/), with funding from NERC grant NE/M000869/1. Roughness here, and in the wider literature, is defined as the variation in bed elevation (in the vertical) at the ice-bed interface, over a given length-scale. These two metrics calculate/quantify this variation in different ways: one shows topographic-scale roughness, calculated from the variation in along-track topography (bed elevation measurements derived from the radar pulse); and the other shows scattering-derived roughness, calculated from quantifying characteristics of each bed-echo (the return from the radar pulse at the ice-bed interface). No credit. completed Jordan, Tom Univeristy of Bristol Researcher author Siegert, Martin Imperial College London Researcher author Williams, Chris University of Bristol Researcher author Bamber, Jonathan University of Bristol Researcher author Cooper, Michael University of Bristol Researcher author Schroeder, Dustin Stanford University Researcher author NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact asNeeded completed EARTH SCIENCE > Land Surface > Topography > Surface Roughness EARTH SCIENCE > Cryosphere > Glaciers/Ice Sheets theme Global Change Master Directory (GCMD) Science Keywords 2026-01-27 publication 23 Global Change Data Center, Science and Exploration Directorate, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA) Greenbelt MD United States of America https://earthdata.nasa.gov/about/gcmd/global-change-master-directory-gcmd-keywords Global Change Master Directory (GCMD) Keywords The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. information publisher Geophysics Ice penetrating radar Radio-echo sounding Scattering Subglacial roughness Topography theme Greenland Arctic place Land cover Elevation theme GEMET - INSPIRE themes, version 1.0 2021-01-06 revision otherRestrictions no limitations to public access otherRestrictions no limitations license Open Government Licence v3.0 otherRestrictions This data is governed by the NERC Data Policy: https://www.ukri.org/who-we-are/nerc/our-policies-and-standards/nerc-data-policy/ otherRestrictions This data is governed by the NERC data policy and supplied under Open Government Licence v.3 otherRestrictions No restrictions apply. url url largerWorkCitation url url crossReference textTable eng utf8 environment geoscientificInformation -80.0 10.0 60.0 90.0 1993-01-01 2016-12-31 It is recommended that careful attention be paid to the contents of any data, and that the author be contacted with any questions regarding appropriate use. If you find any errors or omissions, please report them to polardatacentre@bas.ac.uk. NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information distributor bytes 1 https://ramadda.data.bas.ac.uk/repository/entry/show/?entryid=6071926f-32e0-4681-a50d-aab08f42c08a WWW:LINK-1.0-http--link Get Data Download data download dataset Methodology: The first file, TopoR_icemask.csv, shows topographic-scale roughness, calculated from the variation in along-track topography (bed elevation measurements derived from the radar pulse) at a 200 m length-scale (the bin size used). This dataset presents the spatial pattern of roughness beneath the ice, clipped to ice mask, and filtered with respect to direction of flow. As this data is filtered with respect to flow, it allows for study of anisotropy in roughness (with regards to surface flow direction). TopoR_icemask.csv includes data from all seasons from 1993 - 2016 campaigns. This dataset is derived using a moving 'bin' to calculate root mean square (rms) height for CReSIS along-track topography data (L2 RDS data). The flow filtering is done using Joughin et al (2016b) ice surface velocity mosaic. The second file, ScatR_icemask.csv, shows scattering-derived roughness, calculated from quantifying characteristics of each bed-echo (the return from the radar pulse at the ice-bed interface). A roughness 'value' (expressed in 'metres') is inverted from the 'abruptness' (or pulse peakiness) of the bed return using a scattering model. Theoretically, this dataset presents the spatial pattern of roughness sensitive to roughness between the scale of the wavelength (order meter) and the Fresnel zone (order hundred meters) beneath the ice, clipped to ice mask. The 'scattering derived' roughness provides a more fine-scale roughness value (i.e. presents more information about roughness at scales less that 200 m). ScatR_icemask.csv includes data from CReSIS seasons: 2011-2014 P3; 2011 TO, 2009 TO, 2008 TO, 2006 TO, 2005 TO, 2010 DC8. This dataset is calculated from bed-echo characteristics, using a scattering model, to invert rms height (scattering-derived roughness) from waveform abruptness; this is calculated using the CReSIS data (L1 RDS). For the complete methodology, please see Cooper et al. (in prep.) Data collection: Data was collected with a Multichannel Coherent Radar Depth Sounder (MCoRDS) developed by the Center for Remote Sensing of Ice Sheets (CReSIS). Data quality: Quality control was taken from the original data source; only 'csv_good' files were used, and where appropriate 'high quality' picks, as per the CReSIS radar depth sounder documentation (see ftp://data.cresis.ku.edu/data/rds/rds_readme.pdf). 'csv_good' files only contain data points where the ice surface and ice bottom were detected. Both datasets are point data. For TopoR_icemask.csv, each point is the mid-point of a 200 m 'bin'. asNeeded completed