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Greenland

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  • This dataset has been produced as part of the Theme 5 (Cryosphere and Polar Oceans) in the National Centre for Earth Observation which aims to use new EO data to quantify changes in the mass balance of the cryosphere and to develop new models to represent the relevant processes in coupled climate prediction models. This dataset holds timeseries of Greenland glacier calving front fluctuations as maps and backscatter intensity images for the period March-July 2011. The dataset consists of 38 SAR backscatter images acquired every 3 days between the 12th March and 1st July 2011 during the ERS-2 3-day campaign. The backscatter data were transformed to map coordinates using the GLAS/ICESat 1 km Laser Altimetry Digital Elevation Model of Greenland which is provided at Polar Stereographic grids (DiMarzio, J., Brenner, A., Schutz, R., Schuman, A. & Zwally, H.J. (2007): GLAS/ICESat 1 km laser altimetri digital elevation model of Greenland. Boulder, Colorado USA: National Snow and Ice Data Centre. Digital media).

  • The Greenland Flow Distortion EXperiment, based in Keflavik, Iceland, took place during February 2007. Its aim was to improve the understanding and ability to predict interactions between the atmospheric circulation and the topography of Greenland, both locally and downstream over Western Europe. Hitherto rare in situ observations of high-impact weather systems and their associated air-sea fluxes in the coastal seas of Greenland, were obtained and will be used to improve the numerical modelling and prediction of these weather systems, and thus improve the quality of the atmospheric forcing fields that are essential for accurate atmosphere-ocean coupling and the thermohaline circulation. These measurements will also be used to improve the numerical modelling and prediction of high-impact weather systems over Europe through the use of targeted observations upstream in sensitive areas of the flow. This project investigates the role of Greenland in defining the structure and the predictability of both local and downstream weather systems, through a programme of aircraft-based observation and numerical modelling. The Greenland Flow Distortion Experiment (GFDex) will provide some of the first detailed in situ observations of the intense atmospheric forcing events that are thought to be important in modifying the ocean in this area (but are presently poorly understood): namely tip jets, barrier winds and mesoscale cyclones. Tip jets form at the southern tip of Greenland, at Cape Farewell, through the forcing of flow over and around the topography. Barrier winds occur when the large-scale flow is piled up against the southeast coast of Greenland, forcing winds parallel to the coast. While located off this southeast coast is an area of frequent mesoscale cyclogenesis. GFDex will also investigate Greenlands role in atmospheric flow predictability by carrying out upstream observations that are targeted at investigating the sensitivity of the downstream flow to the details of the upstream flow and at improving subsequent forecasts over Europe. Greenlands flow distortion can trigger large-scale atmospheric Rossby waves which influence weather systems thousands of kilometres away and several days later. These waves are by nature predictable, so by adapting our observing strategy to target specific areas, improvements in subsequent forecasts over the United Kingdom are possible. Numerical modelling experiments after the field campaign will be used to assess any improvements from the additional targeted observations. While further numerical modelling studies of the high impact local weather systems will be evaluated and refined using the aircraft-based observations. This will increase our understanding of these systems and, through comparisons with other observations and data sets, provide accurate fields of air-sea heat and moisture fluxes for driving ocean and climate models.

  • The Greenland Ice Sheet CCI project aims to maximize the impact of ESA satellite data on climate research, by analysing data from ESA Earth Observation missions such as ERS, Envisat, CryoSat, GRACE and the new Sentinel series of satellites. Over the last decade, the Greenland Ice Sheet has shown rapid change, characterized by rapid thinning along the margins, accelerating outlet glaciers, and overall increasing mass loss. The state of the Greenland Ice Sheet is of global importance, and has consequently been included in the ESA CCI Programme as a monitored Essential Climate Variable (ECV). The project is producing data products of the following five parameters, which are important in characterizing the Greenland Ice Sheet as an Essential Climate Variable: Surface Elevation Change (SEC) gridded data from radar altimetry; Ice Velocity (IV) gridded data from synthetic aperture radar interferometry and feature tracking; Calving Front Location (CFL) time series of marine-terminating glaciers; Grounding Line Location (GLL) time series of marine-terminating glaciers; Gravimetry Mass Balance (GMB) maps and time series.

  • This dataset contains a time series of ice velocities for the Upernavik glacier in Greenland between 1992 and 2010. This dataset has been produced by the ESA Greenland Ice Sheet Climate Change Initiative (CCI) project. This dataset consists of a time series of Ice velocity maps which have been generated from SAR data from the ERS-1 and ERS-2, ENVISAT and the ALOS satellites. The data are supplied on a 500m polar stereographic grid. The ice velocity product contain the horizontal components, vN and vE, of the total velocity vector, which is derived from radar measurements assuming surface parallel flow. The used digital elevation model of the surface is also supplied. The North and East velocities at any grid points are given in a local geographic north-east coordinates system (and not in the used grid map projection system).

  • This dataset has been produced as part of the Theme 5 (Cryosphere and Polar Oceans) in the National Centre for Earth Observation which aims to use new EO data to quantify changes in the mass balance of the cryosphere and to develop new models to represent the relevant processes in coupled climate prediction models. This dataset holds timeseries of Greenland glacier velocity fluctuations as maps for the period March-July 2011. The 37 velocity maps were derived from SAR data acquired during the 2011 ERS-2 3-day campaign. The velocity maps are 3-day velocity averages and are given in meters per year (m/y) (magnitude values). The name of the velocity files provides the start and end date of each 3-day period. The velocity fields were transformed to map coordinates using the GLAS/ICESat 1 km Laser Altimetry Digital Elevation Model of Greenland which is provided at Polar Stereographic grids (DiMarzio, J., Brenner, A., Schutz, R., Schuman, A. & Zwally, H.J. (2007)): GLAS/ICESat 1 km laser altimetri digital elevation model of Greenland. Boulder, Colorado USA: National Snow and Ice Data Centre. Digital media).

  • This dataset contains grounding lines for 5 North Greenland glaciers, derived from SAR Interferometery data from the ERS-1 and -2 satellites. Data was produced as part of the ESA Greenland Ice Sheets Climate Change Initiative (CCI) project by ENVEO, Austria. The grounding line separates the floating part of a glacier from the grounded part. Processes at the grounding lines of floating marine termini of glaciers and ice streams are important for understanding the response of the ice masses to changing boundary conditions and for establishing realistic scenarios for the response to climate change. The grounding line location product is derived from InSAR data by mapping the tidal flexure and is generated for a selection of the few glaciers in Greenland, which have a floating tongue. In general, the true location of the grounding line is unknown, and therefore validation is difficult for this product. Remote sensing observations do not provide direct measurement on the transition from floating to grounding ice (the grounding line). The satellite data deliver observations on ice surface features (e.g. tidal deformation by InSAR, spatial changes in texture and shading in optical images) that are indirect indicators for estimating the position of the grounding line. Due to the plasticity of ice these indicators spread out over a zone upstream and downstream of the grounding line, the tidal flexure zone (also called grounding zone).

  • This dataset contains a time series of ice velocities for the Upernavik region in Greenland between 1992-2010, and has been produced by the ESA Greenland Ice Sheet Climate Change Initiative (CCI) project. The data consists of an ice velocity time series derived from intensity-tracking of ERS-1/2, ASAR and PALSAR data acquired between 02-01-1992 and 22-08-2010. It provides components of the ice velocity and the magnitude of the velocity. The data are provided on a polar stereographic grid (EPSG3413: Latitude of true scale 70N, Reference Longitude 45E). The horizontal velocity is provided in true meters per day, towards the EASTING(x) and NOTHING(y) directions of the grid, and the vertical displacement (z), derived from a digital elevation model, is also provided. Please note that the previous versions of this product provided the horizontal velocities as true East and North velocities. Both a single NetCDF file (including all measurements and annotation), and separate geotiff files with the velocity components are provided. The product was generated by GEUS. For further information please see the Product User Guide (v2.0). Please note - this product was released on the Greenland Ice Sheets download page in June 2016, but an earlier product (also accidentally labelled v1.1) was available through the CCI Open Data Portal and the CEDA archive until 29th November 2016. Please now use the later v1.1 product.

  • This dataset provides the Gravitational Mass Balance (GMB) product derived from gravimetry data from the GRACE satellite instrument, by TU Dresden. The data consists of two products: a mass change time series for the entire Greenland Ice Sheet and different drainage basins for the period April 2002 to August 2016; and mass trend grids for different 5-year periods between 2003 and 2016. This version (1.3) is derived from GRACE monthly solutions from the CSR RL06 product. The mass change time series contains the mass change (with respect to a chosen reference month) for all of the Greenland Ice Sheet and each individual drainage basin. For each month (defined by a decimal year) a mass change in Gt and its associated error (also in Gt) is provided. The mass trend grid product is given in units of mm water equivalent per year. Mass balance is an important variable to understand glacial thinning and ablation rates to enable mapping glacier area change. The time series allows the longer term comparison of trends whereas the mass trend grids provide a yearly snapshot which can be further analysed and compared across the data set. Basin definitions and further data descriptions can be found in the Algorithm Theoretical Baseline Document (ST-DTU-ESA-GISCCI-ATBD-001_v3.1.pdf) and Product Specification Document (ST-DTU-ESA-GISCCI-PSD_v2.2.pdf) which are provided on the Greenland Ice Sheet CCI project website. This GMB product has been produced by TU Dresden for comparison with the existing GMB product derived by DTU Space. Please cite the dataset as follows: Groh, A., & Horwath, M. (2016). The method of tailored sensitivity kernels for GRACE mass change estimates. Geophysical Research Abstracts, 18, EGU2016-12065

  • This dataset contains a time series of ice velocities for the Jakobshavn Isbrae glacier in Greenland, generated from Sentinel-1 SAR data acquired from 11/10/2014 and 02/06/2016. It has been produced by the ESA Greenland Ice Sheet Climate Change Initiative (CCI) project. Data files are delivered in NetCDF format at 250m grid spacing in North Polar Stereographic projection (EPSG: 3413). The horizontal velocity components are provided in true meters per day, towards the EASTING(x) and NORTHING(y) directions of the grid.

  • This dataset contains ice velocities for the Greenland Northern Drainage Basin for winter 1991-1992, which have been produced as part of the ESA Greenland Ice Sheet Climate Change Initiative (CCI) project. The data has been derived from intensity-tracking of ERS-1 Ice phase (3 days repeat) data aquired between 29th December 1991 and 22nd March 1992. The data are provided on a polar stereographic grid (EPSG3413: Latitude of true scale 70N, Reference Longitude 45E). The horizontal velocity is provided in true meters per day, towards EASTING(x) and NORTHING(y) direction of the grid, and the vertical displacement (z), derived from a digital elevation model, is also provided. (Please note that in earlier versions of this product the horizontal velocities were provided as true East and North velocities). Both a single NetCDF file (including all measurements and annotation), and separate geotiff files with the velocity components are provided. The product was generated by DTU Space - Microwaves and Remote Sensing. Please note - this product was released on the Greenland Ice Sheets download page in June 2016, but an earlier product (also accidentally labelled v1.1) was available through the CCI Open Data Portal and the CEDA archive until 29th November 2016. Please now use this later v1.1 product.