WEBVTT FILE

1
00:00:00.000 --> 00:00:03.990
>>Interviewer: As we enter the dog days of summer in the United States,

2
00:00:04.010 --> 00:00:07.990
things are heating up even more farther north with melting Arctic sea

3
00:00:08.010 --> 00:00:12.000
ice. And here to join us from NASA's Goddard Space Flight Center in Greenbelt,

4
00:00:12.020 --> 00:00:16.010
Maryland is Dr. Nathan Kurtz. Thanks for joining us. >>Nathan: Hi, thanks for

5
00:00:16.030 --> 00:00:20.030
having me. >>Interviewer: The Arctic is losing sea ice at a faster rate in recent years.

6
00:00:20.050 --> 00:00:24.050
How are things looking this year, and what are we seeing in the long-term trend?

7
00:00:24.070 --> 00:00:28.050
>>Nathan: Well throughout the summer, Arctic sea ice melts, and as the

8
00:00:28.070 --> 00:00:32.070
ice becomes thinner, some of the ice is not able to stay around

9
00:00:32.090 --> 00:00:36.080
as long during the summer. So this year what we're seeing is, melting is

10
00:00:36.100 --> 00:00:40.090
reaching a minimum extent of ice. And it's looking to be about

11
00:00:40.110 --> 00:00:44.090
the sixth to eighth lowest on the satellite record. So a slight rebound from

12
00:00:44.110 --> 00:00:48.130
the past year and 2012, where it was a record low, but

13
00:00:48.150 --> 00:00:52.130
in the long-term average what we've done, we've seen about a third of the ice

14
00:00:52.150 --> 00:00:56.180
cover is gone, about two thirds of the volume and about half the thickness

15
00:00:56.200 --> 00:01:00.190
has gone. So overall the long-term trend is that we're

16
00:01:00.210 --> 00:01:04.190
losing ice. >>Interviewer: Why are we seeing these

17
00:01:04.210 --> 00:01:08.200
changes in the Arctic? >>Nathan: Well we're seeing these changes because the ice

18
00:01:08.220 --> 00:01:12.210
is becoming thinner. It's not able to survive so long throughout the summer,

19
00:01:12.230 --> 00:01:16.220
we're also seeing these changes due to rising global temperatures. So the Arctic

20
00:01:16.240 --> 00:01:20.230
is increasing about two to three times the global average in terms of the

21
00:01:20.250 --> 00:01:24.240
temperature. And what this is doing is this is melting the temperature, and ice

22
00:01:24.260 --> 00:01:28.240
is a great bright reflector, it reflects a lot of the Sun's energy.

23
00:01:28.260 --> 00:01:32.250
Whereas the ocean is dark, it absorbs the energy. So as the ocean

24
00:01:32.270 --> 00:01:36.250
absorbs the energy because of the melting ice, it increases temperatures

25
00:01:36.270 --> 00:01:40.250
and this further melts the ice. We see a continued feedback

26
00:01:40.270 --> 00:01:44.310
of increasing temperatures and loss of ice.

27
00:01:44.330 --> 00:01:48.320
>>Interviewer: What is NASA doing to understand these changes?

28
00:01:48.340 --> 00:01:52.320
>>Nathan: NASA has a variety of satellites and aircraft which are used to study

29
00:01:52.340 --> 00:01:56.320
these changes. Next week we're launching the

30
00:01:56.340 --> 00:02:00.340
ARISE mission, which is meant to study the interaction of clouds and sea ice.

31
00:02:00.360 --> 00:02:04.390
So the ARISE mission will be flying through both

32
00:02:04.410 --> 00:02:08.400
clouds and over sea ice taking measurements of both aspects.

33
00:02:08.420 --> 00:02:12.400
And so clouds have an interesting impact on the climate.

34
00:02:12.420 --> 00:02:16.430
They're very important regulators of the climate. So,

35
00:02:16.450 --> 00:02:20.460
ARISE will study this. NASA is also launching ICESat-2 in about two years,

36
00:02:20.480 --> 00:02:24.640
which uses a laser to range to the surface.

37
00:02:24.660 --> 00:02:28.680
And this allows us to get an idea of how thick the sea ice and also how

38
00:02:28.700 --> 00:02:32.680
thick ice is on land, and how these are changing and give us a better perspective

39
00:02:32.700 --> 00:02:36.690
about how ice is changing on the planet. >>Interviewer: How will these

40
00:02:36.710 --> 00:02:40.690
changes affect the United States? >>Nathan: Well, these

41
00:02:40.710 --> 00:02:44.690
changes actually can have a large impact on the US.

42
00:02:44.710 --> 00:02:48.700
In particular, what's being studied now is the connection between

43
00:02:48.720 --> 00:02:52.710
the warming in the Arctic, loss of sea ice, and changes to the jet stream.

44
00:02:52.730 --> 00:02:56.900
So the jet stream is being changed because we have this

45
00:02:56.920 --> 00:03:00.900
more meandering cycle, it's these up and down bumps, these

46
00:03:00.920 --> 00:03:04.920
north and south bumps, they become larger, they become more extreme.

47
00:03:04.940 --> 00:03:08.930
And this brings more extreme weather to different parts of the US. And

48
00:03:08.950 --> 00:03:12.940
as the jet stream is changing, it's also

49
00:03:12.960 --> 00:03:16.960
becoming more stationary in points, bringing different weather to the US.

50
00:03:16.980 --> 00:03:20.970
>>Interviewer: Where can we learn more? >>Nathan: You can go to

51
00:03:20.990 --> 00:03:25.150
NASA.gov/EarthRightNow to learn more. You can learn more about the NASA missions

52
00:03:25.170 --> 00:03:29.180
that I talked about. You can see

53
00:03:29.200 --> 00:03:33.180
or download NASA data, and you can also see some really amazing pictures and

54
00:03:33.200 --> 00:03:37.190
videos of our home planet. >>Interviewer: Dr. Nathan Kurtz, thank you very much

55
00:03:37.210 --> 00:03:40.507
for joining us. >>Nathan: Thank you.