930b782e-dfd2-4b7a-9a88-7cd03c024080 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 2022-04-29 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 UCL CPOM CryoSat2 derived Dynamic Ocean Topography 2011-2021 2022-04-29 creation 2022-04-29 revision 2022-04-29 publication 2022-04-29 released 1.0 https://doi.org/10.5285/930b782e-dfd2-4b7a-9a88-7cd03c024080 doi GB/NERC/BAS/PDC/01642 https://data.bas.ac.uk/ NE/R000654/1 award Please cite this item as: Heorton, H. (2022). UCL CPOM CryoSat2 derived Dynamic Ocean Topography 2011-2021 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/930b782e-dfd2-4b7a-9a88-7cd03c024080 The ocean surface height is constantly varying under the effects of gravity, density and the Earth's rotation. Information on the Ocean surface elevation in polar regions is available from the CryoSat2 Radar instrument. We compare ocean surface elevation to a static geoid product (GOCO03s) to give the part of the ocean surface elevation accountable due to surface currents, the Dynamic Ocean Topography (DOT). This measurement is smoothed over 100 km and gives monthly surface currents. NERC NE/R000654/1 Towards a marginal Arctic sea ice cover. No credit. completed Heorton, Harold University College London 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 > Oceans > Sea Surface Topography 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 Antarctic Ocean surface currents theme Arctic Antarctica place Oceanographic geographical features 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 Data released under Open Government Licence V3.0: otherRestrictions None. url url crossReference url url largerWorkCitation doi doi crossReference doi doi crossReference textTable eng utf8 environment oceans -180.0 180.0 48.0 90.0 2011-01-01 2020-04-30 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 application/x-hdf application/netcdf bytes 445854515 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=930b782e-dfd2-4b7a-9a88-7cd03c024080 WWW:LINK-1.0-http--link Get Data Download data download bytes 445854515 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=930b782e-dfd2-4b7a-9a88-7cd03c024080 WWW:LINK-1.0-http--link Get Data Download data download dataset Methodology: We take UCL CPOM processed CryoSat2 altimetry measurements of sea surface elevation, from the open ocean or from cracks within the sea ice cover. These records are from 4 satellite modes, LRM, SAR Ocean, SAR lead and SARIN lead. We take the UCL13 Mean Sea Surface product to calculate Sea Level Anomaly (SLA) for all 4 modes. We then calculate a monthly mean offset between, in order, LRM to SAR ocean, SAR ocean to SAR lead, SAR lead to SARIN lead, from coincident measurements on a 100 km resolution grid to remove mode bias' compared to the LRM mode SLA. We then use the GOCO03s geoid to calculate the dynamic ocean topography, then removing the bias from the SLA calculation. The DOT is smoothed over a 100 km Guassian kernel, with gradients to this field giving the surface monthly geostrophic currents. Data quality filtering is under taken at every step of the processing. Data collection: CryoSat2 LRM, SAR and SARIN mode radar altimeter. Data quality: This is a level 2 gridded data product that has gone under extensive data quality filtering. Individual elevation measurements are filtered to be for the specific surface type (see above). When gridding the elevation measurements we first trim off the lowest and highest 20th percentiles before calculating the mean. The gridded data product has many missing values for land points where the data is inapplicable. When smoothing the DOT surface we ignore all grid cells in the 1st and 99th precentile and leave these masked similar to a land point. These outlying cells can occur due to satellite altimeter encountering small islands not found in the land mask. As we apply bias correction to the different satellite modes we have to be careful that the satellite was operating in its standard configuration. For example some months have data points in LRM mode where we usually expect SAR mode. These tracks have to be removed. This was performed manually. asNeeded completed