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EARTH SCIENCE > Cryosphere > Glaciers/Ice Sheets > Glacier Mass Balance/Ice Sheet Mass Balance

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  • From May 2009 to May 2013, seven dual-frequency GPS receivers were deployed along a 120 km-long transect in the south-west of the Greenland Ice Sheet. Two additional dual-frequency GPS receivers were deployed perpendicular to longitudinal ice flow at ~14 km inland: one 5 km distant from June 2011 to May 2013, and another 2.5 km distance from May 2012 to May 2013. Each receiver recorded position observations every 10 seconds or 30 seconds (depending on configuration), enabling resolution of horizontal and vertical ice motion. Sites were powered by solar panels and operated 24 hours a day during summer but shut down in the autumn. Absolute ice displacements at each site were obtained for each summer and winter period in the absence of continuous measurements. Position measurements were kinematically corrected relative to an off-ice base station using TRACK (Chen, 1999). Daily velocities were then obtained by differencing across 24-hour periods, whilst continuous velocities were obtained through application of a sliding 6-hour differencing window. At each GPS site we also measured (1) the near-surface air temperature every 15 minutes year-round, (2) net seasonal ablation using ablation stakes, and (3) at several selected sites melt rates using sonic ranging sensors. This version 2 of the dataset updates the previously 2-day temporal resolution of the ice motion records to 1-day resolution. In other respects the dataset has not changed. Funded by NERC, the Carnegie Trust for the Universities of Scotland and The University of Edinburgh. Relevant grants: NE/F021399/1, NE/H024964/1 Studentships: NE/I52830X/1, NE/J500021/1, NE/H526794/1

  • From May 2009 to May 2013, seven dual-frequency GPS receivers were deployed along a 120 km-long transect in the south-west of the Greenland Ice Sheet. Two additional dual-frequency GPS receivers were deployed perpendicular to longitudinal ice flow at ~14 km inland: one 5 km distant from June 2011 to May 2013, and another 2.5 km distance from May 2012 to May 2013. Each receiver recorded position observations every 10 seconds or 30 seconds (depending on configuration), enabling resolution of horizontal and vertical ice motion. Sites were powered by solar panels and operated 24 hours a day during summer but shut down in the autumn. Absolute ice displacements at each site were obtained for each summer and winter period in the absence of continuous measurements. Position measurements were kinematically corrected relative to an off-ice base station using TRACK (Chen, 1999). Daily velocities were then obtained by differencing across 24-hour periods, whilst continuous velocities were obtained through application of a sliding 6-hour differencing window. At each GPS site we also measured (1) the near-surface air temperature every 15 minutes year-round, (2) net seasonal ablation using ablation stakes, and (3) at several selected sites melt rates using sonic ranging sensors. Funded by NERC, the Carnegie Trust for the Universities of Scotland and The University of Edinburgh. Relevant grants: NE/F021399/1, NE/H024964/1 Studentships: NE/I52830X/1, NE/J500021/1, NE/H526794/1

  • Surface melt onset, duration and end date for the Antarctic Peninsula from 1999/2000 to 2016/2017 at a spatial resolution of 2 km, derived from scatterometer data. Years 1999/2000 to 2008/09 are based on QSCAT data and 2009/10 to 2016/17 on ASCAT data.

  • The basal melt rate at a single location beneath Pine Island Ice Shelf was observed using an autonomous phase-sensitive radio echo-sounder (ApRES) during 2014. The ApRES was deployed approximately 10 km from the ice shelf front where the ice was 492 m thick and the ice shelf draft was approximately 422 m. The ApRES was deployed as part of the NERC Ice Sheet Stability Program (iStar). Funding was provided by the NERC Ice Sheet Stability Research Program.

  • Daily outputs on a 7.5 km horizontal resolution grid covering the Greenland Ice Sheet from MARv3.6.2, which is a regional climate model developed for the Polar regions that solves the regional climate and ice sheet surface mass balance. MAR was forced by ERA-Interim re-analysis data.

  • Three datasets of melt season duration in days covering the Antarctic Peninsula for the austral yeas of 2017/2018, 2018/2019 and 2019/2020. The datasets are based on ASCAT GDS Level 1 Sigma0 Swath Grid data from the EUMETSAT archive (archive.eumetsat.int/usc/) and extend an earlier time series based on enhanced QuikSCAT and ASCAT data (doi:10.5285/e3616d28-759e-4cca-8fae-fe398f9552ba). The data are supplied as GeoTIFFs. Funding was provided from the NERC grant NE/L005409/1.

  • Measurements of water discharge, suspended sediment concentration and electrical conductivity during the melt seasons of 2009, 2010, 2011 and 2012 in the proglacial river draining from the tongue of Leverett Glacier, a land-terminating glacier in the south-west of the Greenland Ice Sheet. The measurements were made in a stable bedrock section approximately 2 km downstream from the glacier terminus. Data loggers recorded measurements every 15 minutes from approximately May to August each year. Water depth (stage) was converted to discharge (Q) using season-specific ratings curves derived from repeat dye-dilution injections undertaken across the stage values. Suspended sediment concentration (SSC) was obtained by calibrating turbidity sensor readings with sediment samples taken in-situ and then filtered, dried and weighed. Electrical conductivity (EC) was recorded using a water conductivity probe; the data were filtered for bad values and corrected for temperature, but no smoothing was applied. These version 2 files are presented as CSV lists, with some summary metadata included as comments at the start of each file; they essentially contain the same data as the previous version files.

  • The flow-line model was designed to enable estimation of the age and surface origin for various ice bodies identified within hot-water drilled boreholes on Larsen C Ice Shelf. Surface fluxes are accumulated, converted to thicknesses, and advected down flow from a fixed number of selected points. The model requires input datasets of surface mass balance, surface velocity, vertical strain rates, ice-shelf thickness, and a vertical density profile. This model is part of a larger project. Input datasets such as density profiles and trajectory vectors are available separately. Resolution is dependent on the input datasets. Funding was provided by the NERC grant NE/L005409/1.

  • Ground-penetrating radar (GPR) was used to test glacier ice thickness/glacier bed detectability on debris-covered Himalayan glaciers at a range of frequencies in glacier long- and cross- profiles and at static points. The survey sites were of the Lirung and Langtang Glaciers in the Langtang National Park, Nepal, where debris cover thickness varied from centimetres to several metres. The radar used was the BAS DELORES dipole pulse radar system, operating at 5MHz, 10MHz, 20MHZ and 40MHz. Data were acquired as a stop-go survey at 2-4m intervals on partially snow-covered and entirely debris-covered glacier surfaces in temperatures close to freezing, with a diurnal freeze-thaw cycle. Funding was provided by the NERC grant NE/L013258/1.

  • The Antarctic mass trends have been collated from a combination of different remote sensing datasets. These are trends of yearly elevation changes over Antarctica for the period 2003-2013 due to the different geophysical processes driving changes in Antarctica: ice dynamics, surface mass balance and glacio-isostatic adjustment (GIA). Net trends can be easily calculated by adding together surface and ice dynamics trends. 20 km gridded datasets have been produced for each process, per year (except the GIA solution which is time-invariant). To convert elevation to mass trends, we also provide the density fields for surface (SMB) and GIA processes used in Martin-Espanol et al (2016). These can be directly multiplied by the dh/dt. To convert dh/dt from ice dynamics, simply multiply by the density of ice. Mass smb = dh/dt smb * d surf Mass ice = dh/dt ice * d ice (not provided) Mass gia = dh/dt gia * d rock NERC grant: NE/I027401/1