Greetings all,

As we, in the northern hemisphere in Toulouse, go further into the winter and the cold, the Mercator-Ocean newsletter goes
towards even higher latitudes. The 2007-2008 International Polar Year (IPY) which started last March, marks the opportunity for us to review the state of the art on Polar research. The 2007-2008 IPY emphasizes the need to capture the contemporary and significant changes occurring in Polar Regions. It provides a crucial benchmark for detecting and understanding changes in comparison with past and future data sets and will improve the observational system for a better monitoring of polar areas.

The 2007-2008 IPY celebrates respectively the 125th, 75th and 50th anniversaries of the first and second IPYs and first IGY.
Indeed, the first IPY took place in 1882-1883 and its key concept was that geophysical phenomena could not be surveyed by
one nation alone and that it would require a coordinated international effort. Twelve countries participated, and fifteen
expeditions to the poles were completed (13 to the Arctic, and 2 to the Antarctic). The second IPY took place in 1932-1933 and
investigated the global implications of the newly discovered “Jet Stream” and to what extent Polar observations could improve, weather forecasts. Forty nations participated and forty permanent observation stations were established in the Arctic. In Antarctica, the U.S.A. established the first research station inland from Antarctica’s coast. The International Geophysical Year (IGY) then took place in 1957-58 and celebrated the 75th and 25th anniversaries of the first and second IPYs. A notable political result founded during the IGY was the ratification of the Antarctic Treaty in 1961.

This newsletter is introduced by an article by Gascard, who presents the DAMOCLES program in the Arctic Ocean where 1.5
millions of km2 of ice area melted during the summer of 2007 in comparison with the former 2005 summer minimum (see
figure). The next article by Garric et al. is dealing with the sea ice in the Mercator-Ocean Global 1/4º system assimilating Sea
Surface Temperature, Temperature and Salinity in situ profiles, and Sea Level Anomalies, using the LIM2 sea ice model
(Louvain-la-Neuve Ice Model, version 2). Then comes the description of the new LIM3 sea ice model by Vancoppenolle et al.
Mathiot et al. follow with a description of the sensibility of polynyas to atmospheric forcing. Girard-Ardhuin et al. are describing the sea ice concentration and drift products developed at Ifremer/CERSAT. And last but not the least is an article that gathers 5 international contributions on data assimilation of ice concentration and/or drift.

The next April 2008 newsletter papers will review the current work on global ocean forecast systems. We wish you a pleasant
reading.

• The integrated European project Damocles and the International Polar Year
• Preliminary assessment of sea ice in the global ¼° Mercator Ocean forecasting system
• LIM3, an advanced sea‐ice model for climate simulation and operational oceanography
• Sensitivity of a model of the Ross Ice shelf Polynya to different atmospheric forcing sets
• Arctic and Antarctic sea ice concentration and sea ice drift satellite products at Ifremer/CERSAT
• Sea ice concentration, ice drift and/or ice thickness data assimilation: a review of the work done in Norway, UK, France, Belgium and Canada.