Switched to ASI Version 5.4 on Nov 23

The announced switch to ASI version 5.4 for the daily sea ice concentration data will has taken  place on Nov 23. The only effect is a slight change in file names, as explained here ('v5.4' instead of 'v5').

For backwards compatibility, symbolic links of the HDF and TIFF files are being created which still have the old file name. This will only be done temporarily.

Reprocessed ASI data from 2002 to Oct 2018: Version 5.4

We have just completed reprocessing all ASI ice concentration data based on AMSR-E or AMSR2 data for the  complete period, i.e.,

  • 1 June, 2002 to 4 Oct, 2011 (AMSR-E)
  •  July, 2012 to 17 Nov, 2018 (AMSR2).

The reprocessing has been done for the hemispheric maps only. i.e., Arctic/Antarctic (6.25 km grid spacing) and Arctic3125/Antarctic3125 (3.125 km grid spacing).

The tie points of the ASI algorithm were the same (version 5). However, some other details as the version of GMT (generic mapping tools) used for gridding the data and defining land masks and coast lines have changed over the years. The reprocessed data are therefore consistent with respect to  all this, and have the version number 5.4. The full version number is also part of all file names ('v5.4'); the new files are stored alongside the files of previous versions  5.2 and 5.3 which just have 'v5' in their file names.

The new data being processed every day have been switched to version 5.4 on Nov. 23, 2018 which implies the mentioned change in the file names ('v5.4' instead of just 'v5')

All details about the ASI ice concentration data can be found in the the new ASI user guide

Information

The satellite "Shizuku" (GCOM-W1) that carries AMSR2 (the successor of AMSR-E) has been launched successfully on May 18, 2012. It has been delivering data since August 2012. On Januray 25, 2013, the calibrated brightness temperature data have been released to the public. Since 26 January 2013, we  have been producing daily sea ice concentration maps from these data.

Note that thorough calibration of the AMSR2/ARTIST Sea Ice (ASI) data has not been finished yet.

As the same frequency (89 GHz) is used as on the AMSR-E instrument and the resolution of AMSR2 is similar, the same ARTIST Sea Ice (ASI) algorithm is applied using the same tie points (calibration constants). The data should be used carefully until full calibration of the AMSR2 / ASI sea ice concentrations has been accomplished

Daily AMSR2 Seaice maps

This page presents the AMSR2 sea ice concentrations calculated daily in near real time. The service is part of the GMES project Polar View and of the Arctic Regional Ocean Observing System (Arctic ROOS).

The ASI sea ice concentration algorithm used here has been validated in several studies (Spreen et al. 2005, Spreen et al., 2008). 
However, no warranty is given for the data presented on these pages.

For detailed information on the ASI sea ice concentration data, see the ASI User Guide

 

 

 

Data Archive

All data can be found in the Data Archive. To quickly browse the dataset, please have a look at the Data Browser.

How to cite

Please help maintaining this service by properly citing and acknowledging if you use the data for publications:
Spreen, G., L. Kaleschke, and G.Heygster (2008), Sea ice remote sensing using AMSR-E 89 GHz channels J. Geophys. Res.,vol. 113, C02S03, doi:10.1029/2005JC003384.

Contact

For questions regarding the data please contact Gunnar SpreenChristian Melsheimer, or Georg Heygster.
For questions related to the website and data-browser please contact Malte Gerken.

Institute of Environmental Physics, University of Bremen, Germany.

Notice Archive

On May 4, 2017, we have moved the sea ice processing to a new server. This implied switching  to a newer version of the mapping software GMT (Generic Mapping Tools),  from version 4 to version 5.

In principle, everything should stay as before, with one exception:
The newer GMT version also uses newer and more accurate Antarctic coastlines. However, we will stick with the landmask that comes with the AMSR2 satellite date as it was (though it is not entirely up to date) in order to keep the sea ice extent time series consistent.

If you encounter any inconsistencies or problems with the data, please contact us.