WEBVTT FILE

1
00:00:00.020 --> 00:00:04.030
[music]

2
00:00:04.050 --> 00:00:08.050
[music, rain falling]
Lau: A monsoon is a very

3
00:00:08.070 --> 00:00:12.100
special kind of climate system.

4
00:00:12.120 --> 00:00:16.100
It is classified in terms of a prevailing

5
00:00:16.120 --> 00:00:20.280
strong winds that reverse distinctly as the

6
00:00:20.300 --> 00:00:24.290
season. And also it is described

7
00:00:24.310 --> 00:00:28.320
by a very distinct a very wet and dry season.

8
00:00:28.340 --> 00:00:32.500
The rainfall that falls within that wet season should

9
00:00:32.520 --> 00:00:36.670
be more than sixty percent of the entire year.

10
00:00:36.690 --> 00:00:40.680
Huffman: The fundamental drive for the monsoon, both in India and

11
00:00:40.700 --> 00:00:44.720
other parts of the world, is that there's a large area of land, which gets warm compared

12
00:00:44.740 --> 00:00:48.870
to the surrounding ocean. And that surrounding ocean provides the moisture, which is

13
00:00:48.890 --> 00:00:53.050
then driving the precipitation that constitutes what we think of as

14
00:00:53.070 --> 00:00:57.060
monsoon.
Lau: If you simply look at the Asian monsoon, you

15
00:00:57.080 --> 00:01:01.090
can estimate--the various estimates--more than sixty percent of the world's population

16
00:01:01.110 --> 00:01:05.150
live right in that area. And the monsoon--

17
00:01:05.170 --> 00:01:09.310
the water--provides the freshwater supply for this population.

18
00:01:09.330 --> 00:01:13.330
Not just for the daily life, for agriculture, for the industry. And so

19
00:01:13.350 --> 00:01:17.390
the entire region, the people's livelihoods depend

20
00:01:17.410 --> 00:01:21.430
on the very delicate balance, the water balance, in that region.

21
00:01:21.450 --> 00:01:25.580
Huffman: GPM gives us a chance to look at precipitation around the

22
00:01:25.600 --> 00:01:29.590
world. And so in addition to the hurricanes and typhoons, we're also

23
00:01:29.610 --> 00:01:33.610
looking at the monsoons because those storm systems are very important for driving

24
00:01:33.630 --> 00:01:37.690
floods, and the advancements in GPM

25
00:01:37.710 --> 00:01:41.860
will allow us to do a better job of providing precipitation information so they can make better

26
00:01:41.880 --> 00:01:46.040
forecasts of the floods.
Lau: Monsoon is not just simply a local problem,

27
00:01:46.060 --> 00:01:50.090
a curiosity, it actually has a huge amount of societal

28
00:01:50.110 --> 00:01:54.100
impact in terms of how it changes in that region, the economy

29
00:01:54.120 --> 00:01:58.110
in that region can affect the entire world, as well as many, many things that

30
00:01:58.130 --> 00:02:02.210
happen in that region. GPM has the most advanced dual-frequency

31
00:02:02.230 --> 00:02:06.390
radar that actually measures

32
00:02:06.410 --> 00:02:10.570
the vertical structure of the rainfall itself. And that's very

33
00:02:10.590 --> 00:02:14.740
important.
Huffman: The DPR gives us an unprecendented

34
00:02:14.760 --> 00:02:18.920
capability of teasing out relative sizes of particles, and this is really important for

35
00:02:18.940 --> 00:02:23.100
understanding how the microphysics, the rain process, works,

36
00:02:23.120 --> 00:02:27.130
and the snow process, and also how those then can be represented in

37
00:02:27.150 --> 00:02:31.180
numerical models that are critical for forecasting future events.

38
00:02:31.200 --> 00:02:35.240
Lau: To study the monsoon, one thing we didn't know is to know what we call

39
00:02:35.260 --> 00:02:39.260
the predictability of the monsoon, how well can we predict the monsoon at a time.

40
00:02:39.280 --> 00:02:43.290
And in order to do the prediction, we need to know the variability

41
00:02:43.310 --> 00:02:47.320
very well, and this ranges from daily to weekly, seasonal,

42
00:02:47.340 --> 00:02:51.370
and then to what we call decadal variability.
Huffman: The monsoon was first

43
00:02:51.390 --> 00:02:55.540
named in India, but it turns out that the same driving force happens

44
00:02:55.560 --> 00:02:59.710
in other parts of the world. And so, for example, in the Northern Hemisphere summer

45
00:02:59.730 --> 00:03:03.750
you have monsoon in West Africa, you have the monsoon

46
00:03:03.770 --> 00:03:07.830
in southwestern North America, and then in our winter,

47
00:03:07.850 --> 00:03:11.980
the Southern Hemisphere's summer, there's a monsoon that happens across northern

48
00:03:12.000 --> 00:03:15.990
Australia. The great thing about GPM is that it allows you to see

49
00:03:16.010 --> 00:03:20.010
the rain systems as a whole. You get to see them over the ocean and over the land,

50
00:03:20.030 --> 00:03:24.180
you can see what the transitions are. And so even before it gets to land, where we

51
00:03:24.200 --> 00:03:28.360
have surface observations, we can tell what's going to come in,

52
00:03:28.380 --> 00:03:32.380
we can see what's been happening. And of course scientifically that also allows us

53
00:03:32.400 --> 00:03:36.420
to understand the complete water cycle that's taking place in the South Asia region.

54
00:03:36.440 --> 00:03:48.609
[stream flowing, rain drops, music]