Abstract: In the framework of the European Space Agency (ESA) Climate Change Initiative (CCI) sea ice essential climate variable (ECV) project (SICCI) [Climate Change Initiative Sea_Ice_cci_Project] a suite of Landsat images of both hemispheres were used to evaluate sea-ice concentration (SIC) products based on satellite microwave radiometry. First, surface broadband albedo values were estimated based on channels 2,3,4 (Landsat-5 or -7) or channels 3,4,5 (Landsat-8). Secondly, a supervised classification was employed, classifying the broadband albedo maps into open water, thin ice and thick ice; note that since this classification is based on simple threshold values, the class thin ice may also include a small fraction of bare thicker sea ice; conversely, the class thick ice may also include a small fraction of thin ice covered by frostflowers or a thin but highly reflective snow cover. Thresholds used for the classification are ~0.07 and 0.4 for the open water / thin ice and thin ice / thick ice transition. Resulting maps have been quality checked for artifacts due to cloudy pixels and double scenes. Note that there might a few maps with a slight overlap from two adjacent Landsat images.
TableOfContents: surface type flag (0: open water, 1: thin or bare sea ice, 2: thick or snow-covered ice, 127: missing data or clouds)
Technical Info: dimensions: nominal: 6166 columns x 6000 rows x unlimited; dimensions actual: variable, depends on how the Landsat scene fits into a rectangular bounding box determined by the minimum and maximum values of latitude and longitude of each scene; temporalExtent_startDate: 2003-04-02; temporalExtent_endDate: 2015-12-24; temporalResolution: ~28 s / image; spatialResolution: 30; spatialResolutionUnit: meters; horizontalResolutionXdirection: 30; horizontalResolutionXdirectionUnit: meters; horizontalResolutionYdirection: 30; horizontalResolutionYdirectionUnit: meters; verticalResolution: none; verticalResolutionUnit: none; verticalStart: none; verticalEnd: none; instrumentName: Landsat-5: Thematic Mapper (TM), Landsat-7: Enhanced Thematic Mapper (ETM), Landsat-8: Operational Land Imager (OLI); instrumentType: optical sensor; instrumentLocation: Landsat-5, Landsat-7, Landsat-8; instrumentProvider: NASA
Methods: [1] http://esa-cci.nersc.no/?q=documents#/Public/Documents from phase 2/D4.1_SICCI_P2_PVIR-SIC_Issue_1.1.pdf; [2] Knap, W. H., Brock, B. W., Oerlemans, J., and Willis, I. C.: Comparison of Landsat TM-derived and ground-based albedos of Haut Glacier d Arolla, Switzerland. Int. J. Rem. Sens., 20(17), 3293-3310, 1999; [3] Koepke, P., Removal of Atmospheric Effects from AVHRR albedos, J. Appl. Meteorol., 28, 1341-1348, 1989; [4] Barsi, J. A., Kenton, L., Kvaran, G., Markham, B. L., and Pedelty, J. A.: The spectral response of the Landsat-8 operational land imager. Rem. Sens., 6(10), 10232-10251, https://doi.org/10.3390/rs61010232, 2014; [5] Chander, G., Markham, B. L., and Barsi, J. A.: Revised Landsat-5 Thematic Mapper Radiometric Calibration. IEEE Geosci. Rem. Sens. Lett., 4(3), 490-494, 2007; [6] Zatko, M. C., and Warren, S. G.: East Antarctic sea ice in spring: spectral albedo of snow, nilas, frost flowers and slush, and light-absorbing impurities in snow. Ann. Glaciol., 56(69), 53-64, https://doi.org/10.3189/2015AoG69A574, 2015.
Units: 1
geoLocations:
Northern Hemisphere: westBoundLongitude: -180.0 degrees East; eastBoundLongitude: 180.0 degrees East; southBoundLatitude: 50.0 degrees North; northBoundLatitude: 90.0 degrees North; geoLocationPlace: Northern Hemisphere over water
Southern Hemisphere: westBoundLongitude: -180.0 degrees East; eastBoundLongitude: 180.0 degrees East; southBoundLatitude: -80.0 degrees North; northBoundLatitude: -60.0 degrees North; geoLocationPlace: Southern Hemisphere over water
Size: (files are packed into one zip-file per year)
Northern Hemisphere: 237 files in total (Landsat-5: 133 files in total from: 2003: 15, 2004: 11, 2005: 31, 2006: 16, 2007: 14, 2008: 14, 2009: 25, 2010: 7; Landsat-7: 12 files from 2003; Landsat-8: 92 files in total from: 2013: 11, 2014: 19, 2015: 62); 142.1 Gbyte (zipped: 76.0Gbyte) in total (Landsat-5: 73.4 Gbyte, zipped: 38.8Gbyte, from: 2003: 8.6Gbyte, 2004: 6.3Gbyte, 2005: 17.6Gbyte, 2006: 9.3Gbyte, 2007: 8.0Gbyte, 2008: 8.0Gbyte, 2009: 14.6Gbyte, 2010: 4.1Gbyte; Landsat-7: 7.2 Gbyte, zipped: 3.6 Gbyte; Landsat-8: 61.5 Gbyte, zipped: 33.6Gbyte, from: 2013: 6.8Gbyte, 2014: 12.5Gbyte, 2015: 42.2Gbyte)
Southern Hemisphere: 141 files in total from: 2013: 47, 2014: 61, 2015: 33; 83.5 Gbyte (zipped: 49.6Gbyte) in total from: 2013: 27.3Gbyte, 2014: 37.4Gbyte, 2015: 18.8Gbyte
Format: netCDF
DataSources: https://earthexplorer.usgs.gov/ [last access: 2021-05-21]
Contact: stefan.kern (at) uni-hamburg.de
This is a data set created for the evaluation of sea-ice concentration products derived from satellite passive microwave observations.
