1 00:00:01,060 --> 00:00:05,000 [music] 2 00:00:05,000 --> 00:00:09,000 VO: This is rain and snow. Not just a day. 3 00:00:09,000 --> 00:00:13,000 Or even a year. This is the culmination of 4 00:00:13,000 --> 00:00:17,000 almost twenty years of precipitation, all at once. 5 00:00:17,000 --> 00:00:21,000 Led by the Global 6 00:00:21,000 --> 00:00:25,000 Precipitation Measurement mission, the newest version of the NASA product 7 00:00:25,000 --> 00:00:29,060 called the Integrated Multi-satellitE Retrievals for GPM, 8 00:00:29,060 --> 00:00:33,000 or IMERG analysis, has remastered almost twenty 9 00:00:33,000 --> 00:00:37,060 years of rain and snow, creating a crisper, clearer 10 00:00:37,060 --> 00:00:41,000 and more complete picture than ever before. This marks 11 00:00:41,000 --> 00:00:45,060 a major milestone in the effort to generate a long-term record of 12 00:00:45,060 --> 00:00:49,060 global precipitation. With this two-decade long record 13 00:00:49,060 --> 00:00:53,060 you can see regional and global patterns in unprecedented 14 00:00:53,060 --> 00:00:57,060 detail. Seasons pulse. 15 00:00:57,060 --> 00:01:01,060 Over India and Southeast Asia, 16 00:01:01,060 --> 00:01:05,060 massive monsoon rains shift. 17 00:01:05,060 --> 00:01:09,060 Storm tracks march along in higher latitudes. 18 00:01:09,060 --> 00:01:13,060 The seas bubble in the Southern Ocean, which scientists consider 19 00:01:13,060 --> 00:01:17,060 one of our planet’s last great unknowns. If we look a little 20 00:01:17,060 --> 00:01:21,060 closer, we can see the wettest and driest places on Earth. 21 00:01:21,060 --> 00:01:25,060 Huffman: Extreme high events tend to be very concentrated and very 22 00:01:25,060 --> 00:01:29,060 localized. Whereas, the opposite, what we would call droughts, tend 23 00:01:29,060 --> 00:01:33,060 to be very widespread and sort of diffuse-looking. 24 00:01:33,060 --> 00:01:37,060 VO: The wettest places on the globe occur over oceans, particular in places where 25 00:01:37,060 --> 00:01:41,060 the surrounding land forces air into a converging pattern over 26 00:01:41,060 --> 00:01:45,060 warm waters that provide a lot of evaporation. 27 00:01:45,060 --> 00:01:49,060 For example, off the coast of Indonesia. 28 00:01:49,060 --> 00:01:53,060 As well as off the northwest coast of Colombia. 29 00:01:53,060 --> 00:01:57,000 And just two thousand miles to the south is one of the driest 30 00:01:57,000 --> 00:02:01,000 areas, the Atacama Desert in Chile. 31 00:02:01,000 --> 00:02:05,000 Across the Atlantic, Namibia experiences some of the least rain as well. 32 00:02:05,000 --> 00:02:09,000 Huffman: The interesting thing of the the last two is that they're 33 00:02:09,000 --> 00:02:13,060 next to the ocean, they’re next to cold ocean. And so in fact those dry zones 34 00:02:13,060 --> 00:02:17,000 actually extend over the ocean. We tend not to think of 35 00:02:17,000 --> 00:02:21,000 ocean deserts but, in fact, that’s what’s going on. VO: Over the past two 36 00:02:21,000 --> 00:02:25,060 decades, precipitation has been changing. 37 00:02:25,060 --> 00:02:29,060 What we’re seeing isn’t a change in the overall amount of rainfall, 38 00:02:29,060 --> 00:02:33,000 but rather how that rainfall is distributed. 39 00:02:33,000 --> 00:02:37,000 Huffman: What seems to be happening—and this is still subject to some interpretation—is 40 00:02:37,000 --> 00:02:41,000 that the regions that get more precipitation are getting even more, 41 00:02:41,000 --> 00:02:45,060 and the areas that get less precipitation are getting even less. 42 00:02:45,060 --> 00:02:49,060 You perhaps heard the phrase “The wet get wetter and the dry get drier.” 43 00:02:49,060 --> 00:02:53,060 VO: This long record allows researchers to better test climate models, 44 00:02:53,060 --> 00:02:57,000 by comparing the model’s virtual scenario with decades of real 45 00:02:57,000 --> 00:03:01,000 precipitation. We’re able to go back in time and reanalyze 46 00:03:01,000 --> 00:03:05,060 large-scale events, like El Niño. Huffman: By making these revised 47 00:03:05,060 --> 00:03:09,060 estimates in the past, it gives us better insight into 48 00:03:09,060 --> 00:03:13,060 the behavior of the atmosphere, and it allows people who are doing, say, model 49 00:03:13,060 --> 00:03:17,060 verification to do a more accurate job of verifying their models for that 50 00:03:17,060 --> 00:03:21,060 particular event, which happened in the past, than they could have done at the time. 51 00:03:21,060 --> 00:03:25,000 VO: Improving the models with the past will help predict the future. 52 00:03:25,000 --> 00:03:29,060 And that doesn’t stop with weather forecasts. A long 53 00:03:29,060 --> 00:03:33,060 precipitation record is a vital tool for researchers modeling floods 54 00:03:33,060 --> 00:03:37,060 and landslides, disease outbreaks, 55 00:03:37,060 --> 00:03:41,060 agricultural forecasts. Tracking our main 56 00:03:41,060 --> 00:03:45,060 source of freshwater. All of these applications need 57 00:03:45,060 --> 00:03:49,060 lots of data over many decades to fine tune the 58 00:03:49,060 --> 00:03:53,060 statistics and models that agencies rely upon for making decisions 59 00:03:53,060 --> 00:03:57,060 around the globe. 60 00:03:57,060 --> 00:04:00,260 [music] 61 00:04:00,260 --> 00:04:01,260 62 00:04:01,260 --> 00:04:00,256