WEBVTT FILE 1 00:00:00.030 --> 00:00:02.050 Reporter: NASA's been looking at snow cover from space 2 00:00:02.050 --> 00:00:04.060 for decades now but 3 00:00:04.060 --> 00:00:04.080 they 4 00:00:04.080 --> 00:00:06.100 they're learning a little bit more with the field 5 00:00:06.100 --> 00:00:08.120 campaign using airborne 6 00:00:08.120 --> 00:00:10.130 and ground instruments. 7 00:00:10.130 --> 00:00:12.140 Here to tell us a little bit about is 8 00:00:12.140 --> 00:00:14.150 Dr. Dorothy Hall from NASA's 9 00:00:14.150 --> 00:00:16.160 Goddard Space Flight Center. Thanks for joining us. 10 00:00:16.160 --> 00:00:18.170 Dorothy: Thank you for having me. 11 00:00:18.170 --> 00:00:20.210 Reporter: NASA's satellites can see this snow cover 12 00:00:20.210 --> 00:00:22.240 from space, how does this winter compare 13 00:00:22.240 --> 00:00:24.260 to previous years? 14 00:00:24.260 --> 00:00:26.280 Dorothy: NASA has a fleet of satellites 15 00:00:26.280 --> 00:00:28.290 that measure the 16 00:00:28.290 --> 00:00:30.300 Earth's land, ocean, 17 00:00:30.300 --> 00:00:32.320 and atmosphere and of course that 18 00:00:32.320 --> 00:00:34.360 includes the snow cover such as 19 00:00:34.360 --> 00:00:36.380 you can see here. 20 00:00:36.380 --> 00:00:38.400 Snow cover is highly variable 21 00:00:38.400 --> 00:00:40.410 actually from week to week 22 00:00:40.410 --> 00:00:42.420 month to month and between years. 23 00:00:42.420 --> 00:00:44.440 If you look at the Sierra 24 00:00:44.440 --> 00:00:46.450 Nevada snow pack in 2015 25 00:00:46.450 --> 00:00:48.450 it was only 26 00:00:48.450 --> 00:00:50.470 about 25% of normal. 27 00:00:50.470 --> 00:00:52.510 Where as in 2017 this year 28 00:00:52.510 --> 00:00:54.530 it's a 180% 29 00:00:54.530 --> 00:00:54.540 of normal. 30 00:00:54.540 --> 00:00:56.540 of normal. That's more snow then they've 31 00:00:56.540 --> 00:00:58.550 seen there in about 20 years. 32 00:00:58.550 --> 00:01:00.570 Reporter: So NASA scientist 33 00:01:00.570 --> 00:01:02.580 are in the field right now testing 34 00:01:02.580 --> 00:01:04.630 these advanced technologies to measure snow 35 00:01:04.630 --> 00:01:06.660 like never before. What will these new 36 00:01:06.660 --> 00:01:08.680 measurements tell us about snow? 37 00:01:08.680 --> 00:01:11.710 Dorothy: NASA has been measuring 38 00:01:11.710 --> 00:01:14.710 snow cover from space for decades 39 00:01:14.710 --> 00:01:17.730 but the real challenge now is to measure 40 00:01:17.730 --> 00:01:20.740 snow depth from space because that's 41 00:01:20.740 --> 00:01:23.760 tells us how much water is in the snow 42 00:01:23.760 --> 00:01:26.790 that we need to use for our water resources 43 00:01:26.790 --> 00:01:29.820 so there is a major airborne NASA campaign 44 00:01:29.820 --> 00:01:32.850 going on now where we can 45 00:01:32.850 --> 00:01:35.870 are working on figuring out what is the optimum 46 00:01:35.870 --> 00:01:38.890 combination of instruments that we can use 47 00:01:38.890 --> 00:01:41.920 to measure snow depth from space on a 48 00:01:41.920 --> 00:01:42.930 global basics. 49 00:01:42.930 --> 00:01:45.960 Reporter: Can NASA see falling snow from space too? 50 00:01:45.960 --> 00:01:48.990 Dorothy: Yes we can. 51 00:01:48.990 --> 00:01:52.040 We have the Global Precipitation Measurement Mission 52 00:01:52.040 --> 00:01:54.060 or GPM and 53 00:01:54.060 --> 00:01:57.100 GPM is designed to measure 54 00:01:57.100 --> 00:02:01.120 snow falling and rain falling and we can measure 55 00:02:01.120 --> 00:02:03.140 that from space. 56 00:02:03.140 --> 00:02:05.150 If you look at this animation of 57 00:02:05.150 --> 00:02:08.200 a major storm that hit the east coast of the US 58 00:02:08.200 --> 00:02:11.210 major snow storm in 2015 you can see 59 00:02:11.210 --> 00:02:14.230 layers of snow and 60 00:02:14.230 --> 00:02:17.250 this information, this data is very useful 61 00:02:17.250 --> 00:02:20.260 for improving weather prediction models. 62 00:02:20.260 --> 00:02:23.300 Reporter: Up to 70% of water resources 63 00:02:23.300 --> 00:02:26.340 in the western US come from snow melt, California has been getting 64 00:02:26.340 --> 00:02:29.360 heavy snow and rain recently. Does that mean the drought is over? 65 00:02:29.360 --> 00:02:32.370 Dorothy: Actually it doesn't 66 00:02:32.370 --> 00:02:35.380 mean that it's over. We are getting a lot 67 00:02:35.380 --> 00:02:38.410 of rain, as you know, infact the rain is 68 00:02:38.410 --> 00:02:41.430 over filling many of the reservoirs. 69 00:02:41.430 --> 00:02:44.450 In California, but there's 70 00:02:44.450 --> 00:02:47.450 a long way to go to restore and replenish 71 00:02:47.450 --> 00:02:50.460 the ground water supplies. 72 00:02:50.460 --> 00:02:53.480 The very important ground water supplies in Californina 73 00:02:53.480 --> 00:02:56.510 help with irrigation of crops. 74 00:02:56.510 --> 00:02:59.520 And so this is way we don't consider that the drought 75 00:02:59.520 --> 00:03:02.530 is over. It will take several more years of 76 00:03:02.530 --> 00:03:05.550 above average precipitation to 77 00:03:05.550 --> 00:03:08.570 replenish those ground water supplies. 78 00:03:08.570 --> 00:03:10.580 Reporter: How does snow impact parts of the country 79 00:03:10.580 --> 00:03:12.620 that rarely see any snowfall? 80 00:03:12.620 --> 00:03:14.650 Dorothy: If you walk in 81 00:03:14.650 --> 00:03:16.670 to any super market 82 00:03:16.670 --> 00:03:18.690 and you look at the produce 83 00:03:18.690 --> 00:03:20.710 you realize that about 84 00:03:20.710 --> 00:03:22.720 half of the produce 85 00:03:22.720 --> 00:03:24.750 that we eat 86 00:03:24.750 --> 00:03:26.770 in this country comes from the 87 00:03:26.770 --> 00:03:28.790 central valley of California 88 00:03:28.790 --> 00:03:30.800 and the central valley 89 00:03:30.800 --> 00:03:32.800 gets a lot of it's water for 90 00:03:32.800 --> 00:03:34.800 irrigation of the crops from 91 00:03:34.800 --> 00:03:36.810 snow melt directly from the 92 00:03:36.810 --> 00:03:38.840 Sierra Nevada mountains. 93 00:03:38.840 --> 00:03:40.850 So that directly influences us. 94 00:03:40.850 --> 00:03:42.860 Even if we don't have snow 95 00:03:42.860 --> 00:03:42.870 cover in our particular region where we live. 96 00:03:42.870 --> 00:03:46.900 cover in our particular region where we live. 97 00:03:46.900 --> 00:03:49.910 Reporter: Where can we learn more? 98 00:03:49.910 --> 00:03:53.940 Dorothy: If you go to snow.nasa.gov 99 00:03:53.940 --> 00:03:57.940 you can learn more about the ongoing SnowX campaign 100 00:03:57.940 --> 00:03:57.960 that's going on now in Colorado 101 00:03:57.960 --> 00:04:00.990 that's going on now in Colorado 102 00:04:00.990 --> 00:04:04.010 as well as a lot more information on satellite 103 00:04:04.010 --> 00:04:05.145 remote sensing in general.