The video was directed by Erik Wernquist and the photography is credited to “NASA/JPL/University of Arizona/Goddard Space Flight Center Scientific Visualization Studio,” which kinda makes me want to track down the original sources.
Each year more and more of the Arctic is comprised of “young ice.”
This animation tracks the relative amount of ice of different ages from 1987 through early November 2014. The first age class on the scale (1, darkest blue) means “first-year ice,” which formed in the most recent winter. (In other words, it’s in its first year of growth.) The oldest ice (>9, white) is ice that is more than nine years old.