Dr. Walt Meier: In this animation, we're taking Arctic sea ice
into the third dimension. Here we're looking at the
ice age, which is an indication of thickness. Generally older ice is
thicker ice. And so what you see in this animation is first of all, the ice
pulsing out and in with the seasons.
In winter the ice grows out and expands outward, and in summer it contracts inward as it
melts. in addition, you see the whiter ice
which is the older ice, moving around the Arctic, being pushed around
by winds and currents that move the ice. And what you can see is over the years
the ice pulses around and moves around towards the top
of the coast of Greenland. You see that the older ice eventually moves out of the
Arctic and into the north Atlantic where it melts.
But the ice gets replenished within the Arctic because some of the ice survives
each summer and grows older. And particularly,
in the region north of Alaska called the Beaufort Sea where the ice
spins around in a clockwise direction, called the Beaufort Gyre
and that ice can keep spinning around, often times for several years, and gradually getting older
and thus getting thicker.
Eventually, the ice will spin out of that gyre and go out through Fram Strait.
But in the past, what is happened, we've always had enough ice growth
and ice aging, enough ice surviving the summers, to
replenish the older ice that's lost. But in recent
years, we've seen less replenishment. There's been more melt
during the summer and so the ice that goes out through Fram Strait has not been
compensated by the ice growth. In addition,
especially in recent years, we've seen some pretty remarkable things
in the Beaufort Sea, where that area that used to be a nursery
for the development of older ice, allow the younger
ice to age and mature, what we've seen instead
is the ice is now more broken up, more scattered, and
that's allowing the older ice to melt within the Beaufort Sea.
So we're seeing the Beaufort Sea go from a nursery to a graveyard
for older ice. And as we get towards the
more recent years, much of that oldest ice, the ice that's older than five years
old in the bright white is almost virtually disappeared
from the Arctic Ocean, and the Arctic is now dominated by younger,
and thinner ice.