Daily AMSR2 Sea Ice Maps

The new 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. Starting on 26 January 2013, we produce 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

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 research for developing, validating and improving the retrieval algorithms was done within the EU Integrated Project DAMOCLES (Developing Arctic Modeling and Observing Capabilites 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.

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.

Other products updated regularly

News on service updates and irregularities


Regional maps

More selected regions

↑ back to top

Map of entire Arctic

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

Sea ice map calculated from AMSR2 data using the ARTIST sea ice algorithm (ASI 5).

↑ back to top


Map of entire Antarctic

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

Sea ice map calculated from AMSR2 data using the ARTIST sea ice algorithm (ASI 5).

↑ back to top


Download AMSR2/ASI sea ice concentration data

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

↑ back to top


Data archive

The archive currently reaches back to 1 August, 2012

New archive browse page (interactive)

↑ back to top


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 -Jul 2, 2012 ASI SSMIS F-17, 91 GHz #3. Sep 2010 – Sep 2011 (using SSMIS F-17 data)
5. Jul 3, 2012 to date ASI AMSR2, 89 GHz #3. (same fit parameters used) Jul 3, 2012 to date

(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

Since July 3, 2012, AMSR2 data is displayed which is adapted with the same parameters as its predecessor AMSR-E. The fit parameters are not deduced by comparing it during an overlap period to another time series. Hence, the data ought to be treated with caution until confirmation by independent sources.

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.

↑ back to top


Sea ice minimum 2007 (AMSR-E data)

Sea Ice Minimum 2007

2007 minimum sea ice extent and mean September 2002-2006 and September 1979-1983 sea ice extents.

↑ back to top


All level 1B data are received from the Japan Aerospace Exploration Agency.

The position of the German research vessel Polarstern is provided by the Alfred-Wegener-Institut, Bremerhaven, Germany.

 

AMSR-E stopped operations Oct 4, 2011. AMSR2 maps available.

The AMSR-E instrument has not produced data since Oct 4, 2011. Therefore, the sea ice maps on this page cannot be updated.

The new 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.

To bridge the gap between AMSR-E and AMSR2, we offer a provisional service based on SSMIS data (In the case you have difficulties reaching this page, please check with your system administrator that you are allowed to use port 8084.) These maps have lower resolution, but for compatibility reasons, they are offered at the same grid spacing as the AMSR-E based maps of this site.

Daily AMSR-E Sea Ice Maps (until 4 Oct, 2011)

This page presents the AMSR-E 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 Capabilites 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.

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.

Other products updated regularly

Historic Arctic Sea Ice Minimum 2011

A new historic Arctic sea ice minimum has been reached on 8 September, 2011. For details, see the updated press release of the University of Bremen.

Note that at the end of August 2012, the sea ice extent fell below the 2007 and 2011 minima!



News on service updates and irregularities


Regional maps, Oct 4, 2011

More selected regions

↑ back to top


Arctic, Oct 4, 2011

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

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

↑ back to top


Antarctic, Oct 4, 2011

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

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

↑ back to top


Download AMSR-E/ASI sea ice concentration data (Oct 4, 2011)

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

↑ back to top


Data archive

↑ back to top


Time Series of Sea Ice Extent

See the continued time series, updated with SSMIS-based sea ice data, on the SSMIS page

↑ back to top


Dynamic Sea Ice Information

Sea Ice Animation

Animation of Arctic sea ice concentration
(daily update of the last 21 days; AVI format, ~ 1 MB)

Animation of Antarctic sea ice concentration
(daily update of the last 21 days; AVI format, ~ 1 MB )

Animation of Arctic sea ice concentration
(Jan 2003 to Oct 2011; AVI format, ~ 34 MB)

Animation of Antarctic sea ice concentration
(Jan 2003 to Oct 2011; AVI format, ~ 31 MB)

↑ back to top


Sea ice minimum 2007

Sea Ice Minimum 2007

2007 minimum sea ice extent and mean September 2002-2006 and September 1979-1983 sea ice extents.

↑ back to top


All level 1A data are received from the National Space Development Agency of Japan.

Distributed by: National Snow and Ice Data Center, Boulder, CO, USA. FTP download.

The position of the German research vessel Polarstern is provided by the Alfred-Wegener-Institut, Bremerhaven, Germany.

Date in yyyymmdd:
Navigation
leftArrow prev day
rightArrow next day
upArrow -1 week
downArrow +1 week
PgUp -1 month
PgDn +1 month
Home -1 year
End +1 year
m List MODIS images
Current date
MODIS
Sensor: Style:
Region:
Image Class

Download

PHAROS computed data

On this page you find an overview of the near real time sea ice data products of the IUP. For the research activities, see the PHAROS group home page

Please see the other tabs for more information about the sensors or to browse the data.

AMSR2:
sea ice concentration maps since 2012
AMSR-E:
sea ice concentration maps 2002-2011
SSMIS:
sea ice concentration maps since 2010. Backup solution for AMSR2 with lower resolution
SMOS:
Thickness of thin sea ice, since 2010.
Regions:
regions available for sea ice concentrations maps from AMSR2, AMSR-E and SSMIS. Not all regions are available for all dates.
Data Browser:
Common browsing tool for all data sets above. Recommended because most convenient for data browsing. stepping forward/backward days, weeks, months, years.
Other ice services
.
 

SSMIS Sea Ice Maps of Selected Regions

Experimental New 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 3.125 km for the regional maps, although the resolution of the SSMIS 91 GHz data (footprint size) is 13.2 by 15.5 km. Note within about 20 km of coasts, the data can often not be used for sea ice retrieval - thus the grey zones along the coasts.

News and announcements

Overview over selected regions


Arctic

↑ back to top


Antarctic

↑ back to top


Other Regions

↑ back to top


Data archive

Data files for every region in HDF and GEOTIFF format are also accessible via the data archive.

Grid coordinate files for every region in HDF format for: Arctic/Other regions; Antarctic regions.


Please contact us if you need any other special region.

↑ back to top


SSMIS/DMSP data collected by the US Air Force Weather Agency.

Distributed by: NOAA's Comprehensive Large-Array data Stewardship System (CLASS).

Daily Thickness of Thin Sea Ice Maps


The thickness of thin sea ice (SIT) is daily retrieved from observations of the L-band microwave sensor SMOS (Soil Moisture and Ocean Salinity) in the incidence angle range of 40° to 50°, horizontal and vertical polarization (Huntemann et al., 2014).
Thin sea ice occurs during the freezing season. In the melting season, the thickness of sea ice is highly variable. In addition, the emissivity properties change due to the wetness of the surface and occurrence of melt ponds in the Arctic. Therefore, thickness data are calculated only during the freezing season, that is from October to April in the Arctic and from April to March in the Antarctic. During the melting season, the procedure does not yield meaningful results.
Two versions of the maps of each day are available consecutively:
  1. The SIT is calculated based on SMOS brightness temperatures available in near real time in the BUFR (Binary Universal Form for the Representation of meteorological data) format from INSA/ESAC SMOS Operations Center in Madrid, Spain. In order to reduce the volume of transmitted data, in this format over ocean only each second grid cell of the SMOS DGG (Discrete Global Grid, an Icosahedral Snyder Equal Area with aperture 4, resolution 9 (ISEA 4H9) grid of 15 km resolution) is transmitted.
  2. One day later, the SMOS Level 1C data are transmitted from an ESA server in Sweden to UB and the previous BUFR-based maps are replaced by those based on this complete data set where not grid cells are omitted. The BUFR based data are then deleted.
As the resolution of SMOS at the used incidence angle range is about 40 km, only larger regions of thin ice will be retrieved correctly. The rim of thin ice shown in many cases not necessarily indicates thin ice, but can also be caused by the smearing effect (convolution) of the low resolution.

This service has been developed in the framework of the EU project SIDARUS. After completion of the SIDARUS project end 2013, the service is continued on a best effort base in the context of the Polar View and of the Arctic Regional Ocean Observing System (Arctic ROOS).

The procedure and validation efforts are described in Huntemann et al. (2014) However, no warranty is given for the data presented on these pages.

Please help maintaining this service by properly citing and acknowledging if you use the data for publications:
Huntemann, M., Heygster, G., Kaleschke, L., Krumpen, T., Mäkynen, M., and Drusch, M.: Empirical sea ice thickness retrieval during the freeze up period from SMOS high incident angle observations, The Cryosphere, 8, 439-451, doi:10.5194/tc-8-439-2014, 2014.
 

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

↑ back to top

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.

↑ back to top


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).

↑ back to top


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).
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.

↑ back to top


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)

↑ back to top


Download current SSMIS/ASI sea ice concentration data

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

↑ back to top


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)

↑ back to top


SSMIS/DMSP data collected by the US Air Force Weather Agency.

Distributed by: NOAA's Comprehensive Large-Array data Stewardship System (CLASS).

No warranty, expressed or implied, is made regarding the accuracy or utility of the data!
False ice concentrations can occur due to bad weather systems.


Georg Heygster, Christian Melsheimer, Justus Notholt, Institute of Environmental Physics, University of Bremen, Germany, 2014