1 00:00:12,560 --> 00:00:16,940 In 1978, satellites began continuously observing the polar regions, 2 00:00:17,140 --> 00:00:20,160 and the dynamic beauty of the Arctic sea ice was revealed. 3 00:00:20,760 --> 00:00:23,480 What we expect to be a solid mass of ice is actually 4 00:00:23,480 --> 00:00:24,720 in constant motion. 5 00:00:24,720 --> 00:00:29,090 As researchers continue to seek a deeper understanding of this region, 6 00:00:29,090 --> 00:00:34,250 new information about how the sea ice changes is coming to light. 7 00:00:34,250 --> 00:00:38,560 [Dr. Walt Meier] In this animation, we're taking Arctic sea ice into the third dimension. 8 00:00:38,560 --> 00:00:40,519 Here, we're looking 9 00:00:40,519 --> 00:00:46,780 at the ice age, which is an indicator of thickness. Generally older ice is thicker ice. 10 00:00:46,780 --> 00:00:51,460 [narrator] That's the voice of Dr. Walt Meier, Senior Research Scientist at the National Snow and 11 00:00:51,460 --> 00:00:52,480 Ice Data Center. 12 00:00:53,920 --> 00:00:59,320 [Meier] What you see in this animation is the ice pulsing out and in with the seasons. 13 00:00:59,820 --> 00:01:05,800 In winter, the ice grows out and expands outward; in summer, it contracts inward as it melts. 14 00:01:07,040 --> 00:01:12,460 You see the whiter ice which is the older ice, moving around the Arctic, being pushed 15 00:01:12,460 --> 00:01:16,340 around by winds and currents that move the ice. 16 00:01:20,540 --> 00:01:23,260 Over the years the ice pulses around 17 00:01:23,260 --> 00:01:27,180 and moves around towards the top along the coast of Greenland. 18 00:01:31,460 --> 00:01:37,680 The older ice eventually moves out of the Arctic and into the north Atlantic where it melts. 19 00:01:38,660 --> 00:01:45,630 The ice gets replenished within the Arctic because some of the ice survives each summer and grows older. 20 00:01:45,630 --> 00:01:50,789 And particularly, in the region north of Alaska, called the Beaufort Sea, where the ice spins 21 00:01:50,789 --> 00:01:54,480 around in a clockwise direction, called the Beaufort Gyre, 22 00:01:54,480 --> 00:01:58,120 and that ice can keep spinning around, often times for several years, 23 00:01:58,120 --> 00:02:01,240 gradually getting older and thus getting thicker. 24 00:02:04,520 --> 00:02:09,200 Eventually, the ice will spin out of that gyre and go out through Fram Strait. 25 00:02:10,040 --> 00:02:16,980 In the past, we've always had enough ice growth and ice aging, enough ice surviving the summers, 26 00:02:16,980 --> 00:02:20,240 to replenish the older ice that's lost. 27 00:02:20,860 --> 00:02:24,120 But in recent years, we've seen less replenishment. 28 00:02:24,120 --> 00:02:26,390 There's been more melt during the summer and 29 00:02:26,390 --> 00:02:32,220 so the ice that goes out through Fram Strait has not been compensated by the ice growth. 30 00:02:33,310 --> 00:02:35,900 In addition, especially in recent years, 31 00:02:35,900 --> 00:02:39,600 we've seen some pretty remarkable things in the Beaufort Sea, 32 00:02:39,600 --> 00:02:45,300 where that area that used to be a nursery for the development of the older ice, 33 00:02:45,300 --> 00:02:48,620 allow the younger ice to age and mature, 34 00:02:48,620 --> 00:02:53,720 what we've seen instead is the ice is now more broken up, more scattered, 35 00:02:53,720 --> 00:02:58,640 and that's allowing the older ice to melt within the Beaufort Sea. 36 00:02:59,280 --> 00:03:05,519 So we're seeing the Beaufort Sea go from a nursery to a graveyard for older ice. 37 00:03:05,900 --> 00:03:08,240 And as we get towards the more recent years, 38 00:03:08,240 --> 00:03:12,820 much of that oldest ice--the ice that's older than five years old in the bright white-- 39 00:03:12,820 --> 00:03:16,880 is almost virtually disappeared from the Arctic Ocean, 40 00:03:17,320 --> 00:03:21,140 and the Arctic is now dominated by younger and thinner ice.