WEBVTT FILE 1 00:00:01.167 --> 00:00:02.869 When you think of wildfires, 2 00:00:02.869 --> 00:00:04.838 you may think of destruction. 3 00:00:04.838 --> 00:00:08.908 Skeletal forests, property lost and lives forever changed. 4 00:00:09.676 --> 00:00:12.312 But fires can also bring rejuvenation. 5 00:00:13.246 --> 00:00:17.484 They can renew ecosystems, nourish the soil, and foster new growth. 6 00:00:18.084 --> 00:00:22.956 But climate change is causing these fires to burn larger, longer, and more often. 7 00:00:23.490 --> 00:00:26.059 These larger and more frequent fires damage ecosystems, 8 00:00:26.059 --> 00:00:29.829 disrupt communities, and can even influence the climate. 9 00:00:30.563 --> 00:00:33.333 So, understanding the basics of wildfires 10 00:00:33.333 --> 00:00:36.136 and how they're impacted by climate change, 11 00:00:36.136 --> 00:00:40.440 is key to our ability to predict where and when fires are likely to occur. 12 00:00:40.640 --> 00:00:44.210 As well as remotely detect and track wildfires once they ignite, 13 00:00:44.744 --> 00:00:48.148 and ultimately mitigate their impacts on human health 14 00:00:48.148 --> 00:00:49.582 and the environment. 15 00:00:51.217 --> 00:00:53.686 This is Wildfires 101. 16 00:00:57.357 --> 00:00:59.292 The first thing you should know, 17 00:00:59.292 --> 00:01:02.395 is that wildfires require three key ingredients: 18 00:01:02.395 --> 00:01:06.366 fuel to burn, the right conditions, and a source of ignition. 19 00:01:06.966 --> 00:01:08.668 But what does that actually mean? 20 00:01:10.070 --> 00:01:13.773 So fuel - like needles, leaves, or wood on the forest floor, 21 00:01:13.940 --> 00:01:16.176 is rarely a fire's limiting factor. 22 00:01:16.409 --> 00:01:20.480 And the conditions that are favorable for fire like hot, dry, and windy days, 23 00:01:20.847 --> 00:01:23.983 are becoming more and more common as our climate changes. 24 00:01:24.584 --> 00:01:26.653 Under these “fire weather” conditions, 25 00:01:26.653 --> 00:01:29.189 fuels dry out and become more susceptible to burn. 26 00:01:29.756 --> 00:01:31.357 As for source of ignition? 27 00:01:31.357 --> 00:01:32.959 Well, most of the wildfires 28 00:01:32.959 --> 00:01:36.096 that NASA detects from space are started by people. 29 00:01:36.262 --> 00:01:40.266 Others, usually in the Arctic and boreal regions, are ignited by lightning strikes. 30 00:01:41.201 --> 00:01:44.237 NASA can track these conditions and inform land managers 31 00:01:44.237 --> 00:01:46.272 when an area appears prone to wildfire. 32 00:01:48.308 --> 00:01:51.511 Every day, NASA is able to detect thousands 33 00:01:51.511 --> 00:01:52.912 of new fires from space. 34 00:01:53.413 --> 00:01:55.348 Along with our partners at NOAA, 35 00:01:55.348 --> 00:01:58.418 we use both polar orbiting and geostationary satellites 36 00:01:58.418 --> 00:02:01.821 to get insight as to the structure and evolution of a fire. 37 00:02:02.188 --> 00:02:06.059 Geostationary satellites remain fixed in relationship to the globe, 38 00:02:06.059 --> 00:02:10.163 giving us new images of one hemisphere every 5 to 15 minutes. 39 00:02:10.630 --> 00:02:12.866 However, the resolution is usually coarser 40 00:02:12.866 --> 00:02:14.734 than that of polar orbiting satellites, 41 00:02:14.734 --> 00:02:17.570 which will pass over a fire twice per day. 42 00:02:18.238 --> 00:02:20.373 From over 500 miles above Earth, 43 00:02:20.373 --> 00:02:24.277 these orbiting satellites will detect and characterize thermal anomalies: 44 00:02:24.277 --> 00:02:28.181 locations on the Earth's surface that are hotter than their neighbors, 45 00:02:28.181 --> 00:02:30.817 that can indicate burning associated with new 46 00:02:30.817 --> 00:02:32.652 or existing fire events. 47 00:02:33.653 --> 00:02:36.923 Importantly, these instruments can detect fires at night - 48 00:02:36.923 --> 00:02:39.959 a time when wildfires typically lay down and smolder. 49 00:02:41.561 --> 00:02:45.231 Since the majority of large wildfires lasts for multiple days, 50 00:02:45.231 --> 00:02:48.434 the ability to track them both day and night is instrumental 51 00:02:48.434 --> 00:02:50.803 to helping land managers combat the blazes. 52 00:02:53.806 --> 00:02:56.910 But it's not just the fire itself that's dangerous. 53 00:02:57.644 --> 00:03:00.647 Wildfire smoke can travel for thousands of miles, 54 00:03:00.647 --> 00:03:02.348 having the ability to blanket 55 00:03:02.348 --> 00:03:05.318 large swaths of a continent from a single wildfire. 56 00:03:05.785 --> 00:03:08.188 Smoke from wildfires can reach high altitudes - 57 00:03:08.188 --> 00:03:11.925 between 3 to 6 miles - and travel with the prevailing winds. 58 00:03:12.592 --> 00:03:15.361 This smoke can linger in the air for several weeks, 59 00:03:15.361 --> 00:03:16.396 changing the chemistry 60 00:03:16.396 --> 00:03:17.830 of the atmosphere and reducing 61 00:03:17.830 --> 00:03:19.999 the amount of sunlight reaching the surface. 62 00:03:20.900 --> 00:03:22.202 Smoke that gets trapped near 63 00:03:22.202 --> 00:03:25.638 the ground severely impacts air quality in surrounding communities, 64 00:03:25.638 --> 00:03:28.041 and poor air quality can last for months 65 00:03:28.041 --> 00:03:30.443 as large fires continue to smolder 66 00:03:30.443 --> 00:03:34.047 even after the fire itself has been contained. 67 00:03:35.615 --> 00:03:38.184 Climate change is not only impacting 68 00:03:38.184 --> 00:03:40.486 the size and intensity of wildfires, 69 00:03:40.486 --> 00:03:43.089 but also their frequency in some regions. 70 00:03:43.356 --> 00:03:48.027 NASA has over 22 years of daily fire data to track wildfire trends. 71 00:03:48.027 --> 00:03:51.931 This is important to get a sense of how fire regimes - the historical 72 00:03:51.931 --> 00:03:55.668 frequency of wildfires in a region - are changing over time. 73 00:03:55.802 --> 00:03:58.805 Understanding an ecosystem’s fire regime is important 74 00:03:58.805 --> 00:04:01.941 because in many instances, wildfire is essential 75 00:04:01.941 --> 00:04:04.944 to maintain a mixture of younger and older vegetation. 76 00:04:05.612 --> 00:04:09.549 However, when fires occur too frequently or with increased severity 77 00:04:09.549 --> 00:04:11.451 it can have devastating effects 78 00:04:11.451 --> 00:04:15.989 like destroying habitat, changing soil chemistry and clogging waterways. 79 00:04:16.623 --> 00:04:17.824 Not to mention releasing 80 00:04:17.824 --> 00:04:21.427 greenhouse gases like CO2 and aerosols into the atmosphere. 81 00:04:22.528 --> 00:04:25.598 NASA can study wildfire’s impact on the landscape 82 00:04:25.598 --> 00:04:27.233 by measuring burn scars, 83 00:04:27.233 --> 00:04:30.303 as well as tracking vegetation loss and rate of regrowth. 84 00:04:30.803 --> 00:04:33.640 Having an accurate assessment of a landscape post-fire 85 00:04:33.640 --> 00:04:37.343 is a key part of understanding how ecosystems recover over time. 86 00:04:37.710 --> 00:04:40.313 NASA’s ability to not only track wildfires, 87 00:04:40.313 --> 00:04:42.815 but also the conditions that lead to them, 88 00:04:42.815 --> 00:04:46.152 is essential to our ability to mitigate their impacts. 89 00:04:46.419 --> 00:04:47.920 We're working with land managers 90 00:04:47.920 --> 00:04:50.556 and those on the front lines to give them the tools, 91 00:04:50.556 --> 00:04:52.625 including near real-time data, 92 00:04:52.625 --> 00:04:55.528 to help them make decisions to minimize the risks 93 00:04:55.528 --> 00:04:57.697 and plan for the future.