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]