WEBVTT FILE

1
00:00:00.030 --> 00:00:04.050
[music]

2
00:00:04.070 --> 00:00:08.100
[music]

3
00:00:08.120 --> 00:00:12.120
Narrator: After centuries of exploring the Arctic from the ground, sea

4
00:00:12.140 --> 00:00:16.210
and then by air, a revolution was about to take place.

5
00:00:16.230 --> 00:00:20.240
thanks to our new view from orbit.  [rocket launching]

6
00:00:20.260 --> 00:00:24.250
With the space age in full bloom, the first satellites to take regular images

7
00:00:24.270 --> 00:00:28.300
of Arctic sea ice were TIROS weather satellites

8
00:00:28.320 --> 00:00:32.370
Archival narrator: ... collection of instruments ever assembled to study the use of space vehicles

9
00:00:32.390 --> 00:00:36.430
for comprehensive weather observation. The most important of these being

10
00:00:36.450 --> 00:00:40.440
two videcon cameras. Both record on this

11
00:00:40.460 --> 00:00:44.530
magnetic tape machine, and on command, send their scannings back to Earth.

12
00:00:44.550 --> 00:00:48.530
Narrator: But the TIROS instruments could not see through clouds

13
00:00:48.550 --> 00:00:52.700
or during the long polar night of winter.

14
00:00:52.720 --> 00:00:56.790
Starting in 1967 NASA began testing more advanced satellite instruments

15
00:00:56.810 --> 00:01:00.830
n board research aircraft over the Arctic. In 1972, a new

16
00:01:00.850 --> 00:01:05.010
satellite called Nimbus 5 and its ESMR instrument began four years of

17
00:01:05.030 --> 00:01:09.180
all-weather, all season imagery of sea ice,

18
00:01:09.200 --> 00:01:13.250
and in 1978, Nimbus 7 used its more advanced microwave

19
00:01:13.270 --> 00:01:17.420
instrument, which could for the first time help distinguish young ice from old.

20
00:01:17.440 --> 00:01:21.600
In 1983 The first Atlas of

21
00:01:21.620 --> 00:01:25.790
Antarctic sea ice was published by NASA Goddard researchers,

22
00:01:25.810 --> 00:01:29.830
followed by an Arctic Atlas four years later. Both were used by

23
00:01:29.850 --> 00:01:34.010
scientists and mariners around the globe. In the first few years

24
00:01:34.030 --> 00:01:38.110
of continuous data collection, researchers started to see a slight decline

25
00:01:38.130 --> 00:01:42.170
in the ice, but they reported the decrease was still within the realm of yearly variability,

26
00:01:42.190 --> 00:01:46.210
and not strong enough to tie decisively to a changing climate.

27
00:01:46.230 --> 00:01:50.300
But in 1999, the trend was becoming clear.

28
00:01:50.320 --> 00:01:54.330
The Arctic was losing ice cover at almost 3 percent per decade.

29
00:01:54.350 --> 00:01:58.400
In 2002, NASA launched the Aqua satellite

30
00:01:58.420 --> 00:02:02.600
with Japan’s AMSR-E instrument, which provided even more enhanced

31
00:02:02.620 --> 00:02:06.810
observations of ice extent, and in 2003, NASA

32
00:02:06.830 --> 00:02:10.970
launched ICESat, which had a laser altimeter on board that provided data

33
00:02:10.990 --> 00:02:15.070
for producing maps of ice thickness.

34
00:02:15.090 --> 00:02:19.100
New record summer minimums were reached in ‘99, 2002, and 2005,

35
00:02:19.120 --> 00:02:23.280
but in 2007, a shockingly large decline

36
00:02:23.300 --> 00:02:27.410
stunned the research community, and scientists realized they needed to get a

37
00:02:27.430 --> 00:02:31.470
better handle on not just the surface area of the ice pack, but the thickness as well.

38
00:02:31.490 --> 00:02:35.520
[aircraft noise] New missions started to focus on

39
00:02:35.540 --> 00:02:39.530
sea ice thickness data, including an ongoing NASA airborne campaign

40
00:02:39.550 --> 00:02:43.570
called Operation IceBridge, and the European Space Agency’s Cryosat-2 satellite.

41
00:02:43.590 --> 00:02:47.720
In summer 2012, due in part

42
00:02:47.740 --> 00:02:51.740
to even thinner ice and a strong Arctic cyclone, yet another

43
00:02:51.760 --> 00:02:55.920
minimum was reached. The last few years haven’t set any new records,

44
00:02:55.940 --> 00:03:00.050
but ice extent and volume continue to be well below the levels

45
00:03:00.070 --> 00:03:04.110
scientists first saw when the satellite era began.

46
00:03:04.130 --> 00:03:08.260
Computer models predict Arctic sea ice will continue to shrink in coming years.

47
00:03:08.280 --> 00:03:12.300
With new satellite missions, instruments in the air, and boots on the ground,

48
00:03:12.320 --> 00:03:16.460
researchers will continue to study not only ice cover and thickness

49
00:03:16.480 --> 00:03:20.560
but also how the loss of ice will affect both the Arctic,

50
00:03:20.580 --> 00:03:24.750
and weather and climate patterns worldwide.

51
00:03:24.770 --> 00:03:31.375
[beep beep, beep beep]