Articles | Volume 10, issue 5
The Cryosphere, 10, 2275–2290, 2016
The Cryosphere, 10, 2275–2290, 2016

Research article 28 Sep 2016

Research article | 28 Sep 2016

The EUMETSAT sea ice concentration climate data record

Rasmus T. Tonboe1, Steinar Eastwood2, Thomas Lavergne2, Atle M. Sørensen2, Nicholas Rathmann3, Gorm Dybkjær1, Leif Toudal Pedersen1, Jacob L. Høyer1, and Stefan Kern4 Rasmus T. Tonboe et al.
  • 1Danish Meteorological Institute, Lyngbyvej 100, Copenhagen, 2100, Denmark
  • 2Norwegian Meteorological Institute, P.O. Box 43, Oslo, 0313, Norway
  • 3University of Copenhagen, Juliane Maries Vej 30, Copenhagen, 2100, Denmark
  • 4Integrated Climate Data Center (ICDC) University of Hamburg, Grindelberg 5, Hamburg, 20144, Germany

Abstract. An Arctic and Antarctic sea ice area and extent dataset has been generated by EUMETSAT's Ocean and Sea Ice Satellite Application Facility (OSISAF) using the record of microwave radiometer data from NASA's Nimbus 7 Scanning Multichannel Microwave radiometer (SMMR) and the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSM/I) and Special Sensor Microwave Imager and Sounder (SSMIS) satellite sensors. The dataset covers the period from October 1978 to April 2015 and updates and further developments are planned for the next phase of the project. The methodology for computing the sea ice concentration uses (1) numerical weather prediction (NWP) data input to a radiative transfer model for reduction of the impact of weather conditions on the measured brightness temperatures; (2) dynamical algorithm tie points to mitigate trends in residual atmospheric, sea ice, and water emission characteristics and inter-sensor differences/biases; and (3) a hybrid sea ice concentration algorithm using the Bristol algorithm over ice and the Bootstrap algorithm in frequency mode over open water. A new sea ice concentration uncertainty algorithm has been developed to estimate the spatial and temporal variability in sea ice concentration retrieval accuracy. A comparison to US National Ice Center sea ice charts from the Arctic and the Antarctic shows that ice concentrations are higher in the ice charts than estimated from the radiometer data at intermediate sea ice concentrations between open water and 100 % ice. The sea ice concentration climate data record is available for download at, including documentation.

Short summary
The EUMETSAT sea ice climate record (ESICR) is based on the Nimbus 7 SMMR (1978–1987), the SSM/I (1987–2009), and the SSMIS (2003–today) microwave radiometer data. It uses a combination of two sea ice concentration algorithms with dynamical tie points, explicit atmospheric correction using numerical weather prediction data for error reduction and it comes with spatially and temporally varying uncertainty estimates describing the residual uncertainties.