WEBVTT FILE 1 00:00:00.020 --> 00:00:04.010 [ Slate ] 2 00:00:04.030 --> 00:00:08.190 Well the latest images are telling us that number one it's 3 00:00:08.210 --> 00:00:12.200 been a really warm winter in the Arctic. It's been warm around the globe, but it's been 4 00:00:12.220 --> 00:00:16.380 really warm in the Arctic - record setting warmth. And we've seen that 5 00:00:16.400 --> 00:00:20.390 in the sea ice, which is at one of its lowest levels at this time of year 6 00:00:20.410 --> 00:00:24.410 in the satellite record going back over 35 years. The ice is also 7 00:00:24.430 --> 00:00:28.580 very thin. [ Slate ] 8 00:00:28.600 --> 00:00:32.710 9 00:00:32.730 --> 00:00:36.720 So the difference between sea ice and land ice is that sea ice grows and melts 10 00:00:36.740 --> 00:00:40.730 within the ocean as the ocean cools. Land ice forms 11 00:00:40.750 --> 00:00:44.770 on land because snow falls on it and gets compressed into ice 12 00:00:44.790 --> 00:00:48.780 over time. One of the big differences in the effects of those is that sea ice 13 00:00:48.800 --> 00:00:52.810 because it grows and melts in the oceans does not raise sea level. 14 00:00:52.830 --> 00:00:56.830 It's the land ice and the land ice that melts that is raising sea level. 15 00:00:56.850 --> 00:01:00.850 Sea ice has a big effect on climate though because it reflects 16 00:01:00.870 --> 00:01:04.870 solar energy because of its whiteness compared to the dark ocean. So 17 00:01:04.890 --> 00:01:08.900 sea ice is very important for the climate as well just not for sea level 18 00:01:08.920 --> 00:01:13.080 19 00:01:13.100 --> 00:01:17.090 [ Slate ] The reason we care is because first of all 20 00:01:17.110 --> 00:01:21.100 changes that are happening there, are happening. They're the first indication 21 00:01:21.120 --> 00:01:25.100 of the warming that we're seeing and the most dramatic so far that we're seeing. But they're an indication 22 00:01:25.120 --> 00:01:29.110 of what's coming to the rest of the globe. But it also has an 23 00:01:29.130 --> 00:01:33.120 affect even now because the changes that happen in the 24 00:01:33.140 --> 00:01:37.190 Arctic with the sea ice, it changes the atmospheric circulation patterns. It changes the 25 00:01:37.210 --> 00:01:41.200 the weather patterns and that effect, that doesn't stay 26 00:01:41.220 --> 00:01:45.270 in the Arctic. What happens in the Arctic doesn't stay in the Arctic. 27 00:01:45.290 --> 00:01:49.280 [ Slate ] 28 00:01:49.300 --> 00:01:53.300 Every year the ice goes 29 00:01:53.320 --> 00:01:57.490 it varies from year to year due to the weather, due to natural cycles 30 00:01:57.510 --> 00:02:01.500 but over the 35 plus years now we've seen a very significant downward 31 00:02:01.520 --> 00:02:05.510 trend where every year tends to be lower than the previous year. 32 00:02:05.530 --> 00:02:09.520 [ Slate ] 33 00:02:09.540 --> 00:02:13.550 NASA is launching two missions to the Arctic - Operation IceBridge and 34 00:02:13.570 --> 00:02:17.740 Oceans Melting Greenland. These two missions are 35 00:02:17.760 --> 00:02:21.940 focused on Greenland and the Arctic sea ice. They're 36 00:02:21.960 --> 00:02:26.120 aircraft missions to better understand what is going on in the 37 00:02:26.140 --> 00:02:30.130 Arctic and why these changes are happening and why they're happening so rapidly. 38 00:02:30.150 --> 00:02:34.140 We have a lot of data that we can see these changes happening, but we've also 39 00:02:34.160 --> 00:02:38.170 been surprised by a lot of these changes and we still need to better understand 40 00:02:38.190 --> 00:02:42.180 the processes that are going on and these NASA missions will help 41 00:02:42.200 --> 00:02:46.180 us get the data to better understand what's going on 42 00:02:46.200 --> 00:02:50.190 and what will happen in the future and the impacts of these dramatic changes 43 00:02:50.210 --> 00:02:54.200 in the Arctic and on the rest of the globe. [ Slate ] 44 00:02:54.220 --> 00:02:58.210 You can learn more 45 00:02:58.230 --> 00:03:03.430 about all of the activities going on in the Arctic Operation IceBridge 46 00:03:03.450 --> 00:03:07.440 Oceans Melting Greenland and all of NASA's data and activities at 47 00:03:07.460 --> 00:03:12.272 nasa.gov/Earth or on Twitter @NASAEarth.