This animation is comprised of Envisat ASAR mosaics of the Arctic Ocean and highlights the changes in sea ice between June and September 2008. The dark grey colour represents ice-free areas while blue represents areas covered with sea ice.
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Envisat satellite</div>
<a rel="nofollow" class="external free" href="http://www.esa.int/spaceinimages/Images/2008/09/Changes_in_Arctic_sea_ice_between_June_and_September_2008">http://www.esa.int/spaceinimages/Images/2008/09/Changes_in_Arctic_sea_ice_between_June_and_September_2008</a>