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In 1978, satellites began continuously observing
the polar regions,

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and the dynamic beauty of the Arctic sea ice was revealed.

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What we
expect to be a solid mass of ice is actually

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in constant motion.

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As researchers continue
to seek a deeper understanding of this region,

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new information about how the sea ice changes
is coming to light.

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[Dr. Walt Meier] In this animation, we're taking Arctic sea
ice into the third dimension.

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Here, we're looking

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at the ice age, which is an indicator of thickness.
Generally older ice is thicker ice.

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[narrator] That's the voice of Dr. Walt Meier, Senior
Research Scientist at the National Snow and

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Ice Data Center.

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[Meier] What you see in this animation is the ice
pulsing out and in with the seasons.

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In winter, the ice grows out and expands outward; in
summer, it contracts inward as it melts.

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You see the whiter ice which is the older
ice, moving around the Arctic, being pushed

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around by winds and currents that move the
ice.

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Over the years the ice pulses around

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and moves around towards the top along the
coast of Greenland.

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The older ice eventually moves out of the Arctic and into the north Atlantic where it melts.

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The ice gets replenished within the Arctic because some of the ice survives each summer and grows older.

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And particularly, in the region north of Alaska,
called the Beaufort Sea, where the ice spins

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around in a clockwise direction, called the
Beaufort Gyre,

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and that ice can keep spinning around, often times for several years,

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gradually getting older and thus getting thicker.

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Eventually, the ice will spin out of that
gyre and go out through Fram Strait.

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In the past, we've always had enough ice growth
and ice aging, enough ice surviving the summers,

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to replenish the older ice that's lost.

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But in recent years, we've seen less replenishment.

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There's been more melt during the summer and

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so the ice that goes out through Fram Strait
has not been compensated by the ice growth.

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In addition, especially in recent years,

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we've seen some pretty remarkable things in the Beaufort Sea,

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where that area that used to
be a nursery for the development of the older ice,

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allow the younger ice to age and mature,

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what we've seen instead is the ice is now more broken up, more scattered,

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and that's allowing the older ice to melt within the Beaufort Sea.

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So we're seeing the Beaufort Sea go from a nursery to a graveyard for older ice.

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And as we get towards the more recent years,

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much of that oldest ice--the ice that's older than five years old in the bright white--

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is almost virtually disappeared from the Arctic Ocean,

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and the Arctic is now dominated by
younger and thinner ice.