No data since Oct 21, 2014

There are unexpected maintentance works by the provider of the SSMIS data, currently with no established date for the return of service. For the time being , there will be no updated maps.

AMSR2 / ASI sea ice maps

The satellite しずく "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, and starting from 26 January 2013, we produce daily sea ice concentration maps from the AMSR2 data.

Experimental SSMIS-derived Maps

To replace the missing AMSR-E-derived sea ice maps after the AMSR-E instrument failure on October 4, 2011, we apply the same algorithm (ARTIST sea ice) to the 91 GHz channels of the SSMIS instrument (DMSP satellites), the main difference being the change of frequency from 89 GHz (AMSR-E) to 91 GHz (SSMIS). To achieve the best compatibility, the parameters of the ASI algorithm would need to be adjusted. As we expect the changes would only be marginal, and in order to resume this service as quickly as possible, we refrain from any adjustment here. For compatibility, we keep the grid spacing of 6.25 km, although the resolution of the SSMIS 91 GHz data (footprint size) is 13.2 by 15.5 km

For the described reason, please use these maps carefully. Any feedback is welcome.

Latest SSMIS Sea Ice Maps, 20 Oct, 2014

This page shows SSMIS 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 research for developing, validating and improving the retrieval algorithms was done within the EU Integrated Project DAMOCLES (Developing Arctic Modeling and Observing Capabilities for Long-term Environmental Studies)

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. As we are using SSMIS data instead of AMSR-E data, the quality of the resulting maps has yet to be assessed.

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.



News on service updates and irregularities


Regional maps

More selected regions
Maps of the day before
(i.e. the day before yesterday)

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Arctic

Arctic sea ice extent
Click on the image to enlarge (~1.2 MB).

Sea ice map calculated from SSMIS data using the ARTIST sea ice algorithm (ASI 5).

Arctic sea ice extent (different color code)
Click on the image to enlarge (~500 KB).

False color sea ice map.

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Antarctic

Antarctic sea ice extent
Click on the image to enlarge (~500 KB).

Sea ice map calculated from SSMIS data using the ARTIST sea ice algorithm (ASI 5).

Antarctic sea ice extent (different color code)
Click on the image to enlarge (~300 KB).

False color sea ice map. Note: Ice shelves not properly masked out (cf. map on the left with blue-gray-white color scale).

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Time Series of Sea Ice Extent

The diagrams below show sea ice extent data since 1979. The complete time series is composed of observations from different sensors, using different sea ice concentration retrieval algorithms and adaptations to each other using certain overlap periods:
# Period Algorithm Sensor, Frequencies, Source Adapted to Overlap period
1. 1972 - 2002 NASA Team SMMR & SSM/I, 19 and 37 GHz from NSIDC(1) #2. 1989 - 2002
2. Oct 26, 1978 - Dec 2010 NASA Team Sea ice concentrations from NIMBUS-7 SMMR and DMSP SSM/I-SSMIS passive microwave data, 19 and 37 GHz, from NSIDC(2) reference only, but not part of the time series because of some gaps 1978 - 1988  
3. 2003 - Oct 4, 2011 ASI AMSR-E, 89 GHz #2. 2002 - 2007
4. Oct 5, 2011 to date ASI SSMIS F-17, 91 GHz #3. Sep 2010 ‐ Sep 2011 (using SSMIS F-17 data)

(1): Merged ESMR, SMMR, and SSM/I-SSMIS Sea Ice Extent from NSIDC

(2): See information on this data set at NSIDC

To adapt data from a newer source to the data from an older source, the newer data were linearly transformed such that both mean and standard deviation or the newer time series matched the mean and standard deviation of the older time series in the overlap period.

In addition, the data are smoothed by a 5-day running mean. Consequently, the current day and the day before are only averaged over three respectively four days and might still vary slightly for two (resp. one) days

A note of caution: To avoid erroneous ice concentration along coasts (satellite signal mixed from land and ocean), near coastal-areas have to be excluded. However, the standard flag in the SSMIS data for coastal waters is rather coarse, thus a zone of about 30 km along all coasts is excluded. Especially in the Canadian Archipelago, this results in considerable sea areas not being included in the retrieval. This can only roughly be compensated by the above-mentioned time series adaptation to the previous AMSR-E data (which had higher resolution and a more refined coastal area flag).

As of 28 August, 2012, most other sources also show sea ice extent below the previous record from 2007.

TEST
Diagram: Arctic sea ice extent since 1979
Click on the image to enlarge.

Annual Arctic sea ice extent (total area of at least 15% ice concentration) for selected years since 1979.

Diagram: Antarctic sea ice extent since 1979
Click on the image to enlarge.

Annual Antarctic sea ice extent (total area of at least 15% ice concentration) for selected years since 1979.

Diagram: Arctic sea ice extent during previous 7 years
Click on the image to enlarge.

Annual Arctic sea ice extent (total area of at least 15% ice concentration) for the last 7 years.

Diagram: Antarctic sea ice extent during previous 7 years
Click on the image to enlarge.

Annual Antarctic sea ice extent (total area of at least 15% ice concentration) for the last 7 years.

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Dynamic Sea Ice Information

Sea Ice Animation
Animation of Arctic sea ice concentration
(daily update of the last 31 days; AVI format, ~ 1.7 MB)
Animation of Antarctic sea ice concentration
(daily update of the last 31 days; AVI format, ~ 1.9 MB )

Animation of Arctic sea ice concentration
(Sep 2011 to date, updated monthly; AVI format, ~ 1.6 MB)

Animation of Antarctic sea ice concentration
(Sep 2011 to date, updated monthly; AVI format, ~ 1.6 MB)
The following two experimental animations combine AMSR-E-based and SSMIS-based sea ice maps which might be inconsistent.
"Hybrid"(AMSR-E/SSMIS) Animation of Arctic sea ice concentration, Jan 2003 to April 2012;
AMSR-E until 4 Oct 2011, SSMIS from 5 Oct 2011 (AVI format, ~ 36 MB)
"Hybrid"(AMSR-E/SSMIS) Animation of Antarctic sea ice concentration, Jan 2003 to April 2012;
AMSR-E until 4 Oct 2011, SSMIS from 5 Oct 2011 (AVI format, ~ 33 MB)

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Download current SSMIS/ASI sea ice concentration data

GEOTIFF Arctic Antarctic Geotiff ReadMe
HDF Arctic Antarctic
grid coordinates (HDF) Arctic Antarctic

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Data archive

Note: The archive of SSMIS-based sea ice map has been started recently. It now contains daily sea ice maps since Sept 1, 2010.

New archive browse page (interactive)

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