Daily Maps of Sea Ice for Maritime Safety and Climate Research
ProjectsCompany Profile
Contact
Daily Maps of Sea Ice for Maritime Safety and Climate Research
The IUP (Institute of Environmental Physics) of the University of Bremen provides daily global and regional sea ice maps based on satellite data. They are used by a wordwide community for operational, scientific and general applications, in ship routing and climate research.
Exact and timely information on sea ice cover in the Polar Regions is required for operational shipping, weather prediction and climate research. The IUP has been offering such information since 1999, based on observations of passive microwave and optical satellite observations.
In the Arctic, global warming is several times more pronounced than on global average. Therefore continuous surveying of the Arctic sea ice and climate is required. Because of the hostile environmental conditions in these vast regions, satellite sensors are the best suited means for observations continuous in both space and time. While the standard sea routes are regularly inspected by airborne patrol and with higher resolving satellite sensors, the increasing number of expeditions and passenger cruises requires regular sea ice information covering the complete Arctic and Antarctic, and with decreasing summer sea ice extent, the North East and North West Passages become more and more attractive for commercial cargo traffic. Moreover, retrieval procedures for other sea ice properties like thickness and snow depth are being developed.
Map Generation
The unique feature of the ice concentration maps produced at IUP is the resolution of 6 km for the whole Arctic and Antarctic, obtained by using the highest resolving channels of the microwave sensor AMSR-E (Advanced Microwave Scanning Radiometer on EOS) observing at 89 GHz. Other ice concentration algorithms use lower frequency channels with lower resolution. Microwave sensors have the advantages over optical sensors that they operate independently of day and (polar) night, and that they are not hampered by clouds. The daily maps are composed from the collection of all overpasses of the current day, each covering a stripe of about 1.400 km width. The raw satellite observations obtained from data centres within less than 4 hours are processed at IUP twice per day.
Sea ice concentration,
whole Arctic Aug. 10, 2010.
(Click to enlarge image)
Overlay of MODIS (grey) and AMSR-E image east of Greenland (green)
(click to enlarge image)
Time series Arctic sea ice extent 2003-2010
(click to enlarge image)
Expample 1: Daily AMSR-E MAPS
The left figure shows the Arctic sea ice map as of Aug. 13, 2010, based on data of the passive microwave sensor AMSR-E, with a resolution of 6 km. In addition to the Arctic, daily maps of the Antarctic, and of about 20 smaller regions, the latter with resolution of 3 km, are calculated. The maps are publicly available at www.iup.uni-bremen.de/seaice/amsr. The maps of the preceding day are completed before 4 AM, and at 6 PM maps of the current day are calculated. Maps of specific regions and on thematic statistics are provided on request. E.g., for the research vessel Polarstern of the Alfred Wegener Institute, daily maps centred on the current ship position are sent to the vessel by email.
Example 2: Daily Modis Maps
The middle figure shows a map of the sensor MODIS on AQUA. The high resolution of 1 km allows recognizing distinct ice floes (grey). Ice concentration isolines of 30, 60 and 90 %, are shown in green, yellow and red, respectively. They are based on the AMSR-E data of the same day. Note the good agreement between MODIS and AMSR-E ice information. While the MODIS data have the much higher resolution of 1 km, they need daylight and are hampered by clouds. The volume of the MODIS data allows only processing selected regions of limited extent.
Example 3: Daily Time Series of Ice Extent
The right figure shows, as an example of climatological analysis, the daily variation of the sea ice extent for all the years since 2003. The diagram is updated daily on the sea ice web page. The line corresponding to the current year is shown in red. In this diagram, it ends on Aug. 11, the day of production of this figure. The yearly sea ice minimum is reached in the second half of September. Although the historic minimum of the year 2007 (dark blue) has not been surpassed in the years since then, all annual cycles shown are clearly below the longterm average (dashed). Similar diagrams for the monthly change and for the Antarctic are also daily updated at www.iup.uni-bremen.de/seaice/amsr
Profile:
Institute of Environmental Physics (IUP, Institut für Umweltphysik), University of Bremen
The institute, founded in 1993, uses the tools of physics to investigate the system “Earth” with its components atmosphere, cryosphere and oceans. The most used methods are remote sensing techniques mainly based on satellites, but also on ground and ships. Among the satellite sensors is SCIAMACHY on Envisat. The IUP is the PI institute for SCIAMACHY an optical image spectrometer which allows to document a wide variety of atmospheric trace gases. Another focus of the institute are the Polar Regions, both surface and atmosphere, investigated with microwave and optical satellite sensors.
Contact
Dr. Georg Heygster
Tel.: +49 (0)421 218-62180
Fax: +49 (0)421 218-4555
heygster [at] uni-bremen [dot] de
www.iup.uni-bremen.de
www.iup.uni-bremen.de/seaice/amsr
Institut fur Umweltphysik
Universitat Bremen
Otto-Hahn-Alle 1
28334 Bremen, Germany
Dr. Christian Melsheimer
Tel.: +49 (0)421 218-62181
Fax: +49 (0)421 218-4555
melsheimer [at] uni-bremen [dot] de
www.iup.uni-bremen.de
Institut fur Umweltphysik
Universitat Bremen
Otto-Hahn-Alle 1
28334 Bremen, Germany
Prof. Dr. Justus Notholt
Tel.: +49 (0)421 218-62190
Fax: +49 (0)421 218-4555
jnotholt [at] iup [dot] physik [dot] uni-bremen [dot] de
www.iup.uni-bremen.de
Institut fur Umweltphysik
Universitat Bremen
Otto-Hahn-Alle 1
28334 Bremen, Germany 
