WEBVTT FILE

1
00:00:00.000 --> 00:00:02.180
[weatherman] Over Hagerstown and Martinsburg tomorrow.

2
00:00:02.180 --> 00:00:03.929
[Narrator] Weather forecasters use them to create

3
00:00:03.929 --> 00:00:08.340
the nightly weather report. Airline
pilots use them to learn how to fly

4
00:00:08.340 --> 00:00:14.130
planes experts. Experts use them in virtually every industry and discipline. Their

5
00:00:14.130 --> 00:00:20.939
computer models. At NASA, scientists use
computer models to enhance our

6
00:00:20.939 --> 00:00:28.380
understanding of the Earth,
the solar system and the universe. NASA

7
00:00:28.380 --> 00:00:32.309
satellites orbiting the Earth relay
immense amounts of data back to

8
00:00:32.309 --> 00:00:36.719
scientists on the ground. Who can then
enter that data into computer model

9
00:00:36.719 --> 00:00:44.879
simulations. [Rosenzweig] We have then equations and
then we have computer code which solves

10
00:00:44.879 --> 00:00:51.090
those equations on a day-to-day basis.
[Narrator] NASA is the source for most of the

11
00:00:51.090 --> 00:00:55.739
research satellite observations of the
atmosphere land and oceans.

12
00:00:55.739 --> 00:01:01.500
[Webster] So the NASA scientists will look at the
observational data and make theoretical

13
00:01:01.500 --> 00:01:05.700
projections of what a model might look
like. And they will build a numerical

14
00:01:05.700 --> 00:01:11.040
model based on the data and then run
that on our computers and then compare

15
00:01:11.040 --> 00:01:17.580
that to reality. [Narrator] With rapid increases in
computer technology. Models are becoming

16
00:01:17.580 --> 00:01:21.960
evermore powerful and sophisticated.
Allowing us to simulate our complex

17
00:01:21.960 --> 00:01:28.110
environment in greater detail. NASA uses
a variety of weather models, such as the

18
00:01:28.110 --> 00:01:33.740
Goddard Earth observing system model or
GEOS-5. It creates an extraordinarily

19
00:01:33.740 --> 00:01:37.880
high-resolution realistic looking view
of our atmosphere.

20
00:01:37.880 --> 00:01:43.380
These Geos-5 simulations showcase
the model's ability to capture fine

21
00:01:43.380 --> 00:01:48.420
scale cloud features worldwide. Like the
swirling clouds in the Atlantic Ocean

22
00:01:48.420 --> 00:01:55.619
off the coast of North America. The goal
of weather models is to give the most

23
00:01:55.619 --> 00:02:02.729
accurate prediction of weather over the
next week to ten days. In 2005 when

24
00:02:02.729 --> 00:02:06.479
Hurricane Katrina formed over the
Atlantic Ocean, scientists wanted to

25
00:02:06.479 --> 00:02:11.940
understand the storm. How intense was it? What was its size and structure? And what

26
00:02:11.940 --> 00:02:17.670
would be its final path. NASA satellites
continuously monitored many aspects of

27
00:02:17.670 --> 00:02:22.319
the storm from wind speed, rainfall and
sea surface temperature to the storms

28
00:02:22.319 --> 00:02:27.750
three-dimensional structure. To get a
more complete picture of the storm and

29
00:02:27.750 --> 00:02:32.569
predict its evolution. Scientists entered
the data into a computer model. Then

30
00:02:32.569 --> 00:02:37.080
high-powered supercomputers capable of
trillions of calculations per second

31
00:02:37.080 --> 00:02:42.510
crunched the numbers. This process is
called data assimilation. Data

32
00:02:42.510 --> 00:02:46.980
assimilation is a two-step cycle that
repeats itself whenever new data becomes

33
00:02:46.980 --> 00:02:51.540
available. In the first step, the model
runs forward in time to provide an

34
00:02:51.540 --> 00:02:56.129
estimate of the atmosphere. In the second
step, this estimate gets corrected using

35
00:02:56.129 --> 00:03:01.500
observations. Then the cycle begins again
each step building upon the last and

36
00:03:01.500 --> 00:03:05.330
accumulating the information from
satellite and ground observations.

37
00:03:05.330 --> 00:03:09.750
Weather models are updated every six
hours to include the most current

38
00:03:09.750 --> 00:03:14.069
observations for the next forecast.
This approach prevents the model from

39
00:03:14.069 --> 00:03:18.300
straying too far from reality and acts
as a checksum balance system to achieve

40
00:03:18.300 --> 00:03:22.520
the most accurate forecast.

41
00:03:22.520 --> 00:03:27.420
While weather models for the conditions
for up to 10 days. Climate models predict

42
00:03:27.420 --> 00:03:32.100
trends over much longer periods of time.
[Webster] The climate models that are run at the

43
00:03:32.100 --> 00:03:38.160
NCCS are numerical expressions of the
various processes that make up the

44
00:03:38.160 --> 00:03:42.840
climate. This includes things like land
surface, movement of water in the ocean

45
00:03:42.840 --> 00:03:48.150
and movement of air in the atmosphere.
[Narrator] Just as in weather prediction, data

46
00:03:48.150 --> 00:03:52.400
simulation as a way of bringing all the
observations of the Earth together to

47
00:03:52.400 --> 00:03:57.500
provide an analysis of our climate. One
example of this technique is MERRA the

48
00:03:57.510 --> 00:04:02.720
Modern Era Retrospective Analysis for
Research and Application. MERRA

49
00:04:02.730 --> 00:04:07.440
incorporates data from the entire
satellite record over 30 years of data.

50
00:04:07.440 --> 00:04:12.770
Its results are data encyclopedia that
can be used for research and analysis.

51
00:04:12.770 --> 00:04:17.880
MERRA can help meteorologists understand
the variations associated with specific

52
00:04:17.880 --> 00:04:22.040
weather events in the past. While MERRA
gives us a climate picture across

53
00:04:22.040 --> 00:04:27.140
decades. The Goddard Institute for Space
Studies or GISS can extend that

54
00:04:27.150 --> 00:04:31.740
view across centuries. GISS models have
already unraveled average temperature

55
00:04:31.740 --> 00:04:37.380
trends over 200 years. New GISS simulations
will cover the last 1,000 years to

56
00:04:37.380 --> 00:04:42.360
verify the models accuracy. They'll also
look forward predicting climate trends

57
00:04:42.360 --> 00:04:47.729
to the end of the 21st century. With each
satellite launched we gain millions of

58
00:04:47.729 --> 00:04:52.590
measurements that tell us more about our
planet. Having so much more data will

59
00:04:52.590 --> 00:04:56.880
require increases in computing power to
synthesize this information into

60
00:04:56.880 --> 00:05:01.410
meaningful representations of the
climate system as a whole. [Webster] At Goddard

61
00:05:01.410 --> 00:05:06.060
Space Flight Center we have a tremendous
amount of observational data which is

62
00:05:06.060 --> 00:05:10.950
captured by our satellites. We have
probably the largest collection of Earth

63
00:05:10.950 --> 00:05:15.870
Scientists anywhere in the world. And we
have this new state-of-the-art computing

64
00:05:15.870 --> 00:05:21.270
center. So the combination of the
scientists, the data and the computing

65
00:05:21.270 --> 00:05:28.380
puts us in a unique position to enable
advances in weather climate research.

66
00:05:28.380 --> 00:05:42.600
[music]