How to track a tornado - Karen Kosiba
-
0:06 - 0:08So, I think all good tornado talks
-
0:08 - 0:11need to start with an awesome tornado shot.
-
0:11 - 0:13And this is not that awesome tornado shot.
-
0:13 - 0:15Alright, that was the first tornado I ever saw,
-
0:15 - 0:16it was really cool, it was really scary,
-
0:16 - 0:18and the reason I'm showing it to you guys
-
0:18 - 0:20was because that's why I got into the field in the first place.
-
0:20 - 0:23So, even though it's a bad photograph,
-
0:23 - 0:25it was really cool to be out there the first time.
-
0:25 - 0:27But now I'm taking real tornado footage.
-
0:27 - 0:29Fast forward a few years here.
-
0:29 - 0:30This is a few years ago
-
0:30 - 0:32during a field project called VORTEX2,
-
0:32 - 0:35where myself and a bunch of other scientists were out there
-
0:35 - 0:37surrounding tornadoes with different types of instrumentation
-
0:37 - 0:40and trying to figure out how tornadoes form.
-
0:40 - 0:42So, it's a big question that we're trying to answer.
-
0:42 - 0:43It sounds like a very basic one,
-
0:43 - 0:45but it's something that we're still trying to figure out.
-
0:45 - 0:47We're also still trying to figure out
-
0:47 - 0:49what the winds are like near the surface.
-
0:49 - 0:51We know what the winds are like above building level,
-
0:51 - 0:54but we really don't know what the winds are like at the surface
-
0:54 - 0:57and how that relates to what we're seeing above building level.
-
0:57 - 1:01So, most tornadoes form from what we call supercell thunderstorms,
-
1:01 - 1:02and these supercell thunderstorms
-
1:02 - 1:05are what you commonly think of as tornado-raising storms.
-
1:05 - 1:07They're big, rotating thunderstorms
-
1:07 - 1:10that happen a lot of times in the midsection of the United States.
-
1:10 - 1:12But the problem is that
-
1:12 - 1:14even because they're rotating up above
-
1:14 - 1:16doesn't mean they're rotating at the surface.
-
1:16 - 1:17And when we look at these storms
-
1:17 - 1:18and when we look at these pictures
-
1:18 - 1:20and when we look at the data that we have
-
1:20 - 1:22they all kind of look the same.
-
1:22 - 1:23And it's really problematic
-
1:23 - 1:26if we're trying to make tornado forecasts or tornado warnings
-
1:26 - 1:27because we only want to warn on the storms
-
1:27 - 1:29or forecast about the storms
-
1:29 - 1:31that are going to actually make a tornado.
-
1:31 - 1:33One of the big critical distinguishing features
-
1:33 - 1:35that we think between these storms
-
1:35 - 1:38is something about the rear flank downdraft.
-
1:38 - 1:39So, these big rotating thunderstorms
-
1:39 - 1:43have this downdraft that wraps around the rear edge of it,
-
1:43 - 1:44hence the rear flanking downdraft.
-
1:44 - 1:46But we think how warm that is,
-
1:46 - 1:48how buoyant that air is,
-
1:48 - 1:49and then also how strong the updraft
-
1:49 - 1:51that's wrapping into
-
1:51 - 1:52makes a big difference on whether or not
-
1:52 - 1:54there's going to make a tornado or not.
-
1:54 - 1:56And there's certainly a lot more that goes into it
-
1:56 - 1:58and I'll tell you a little more about that in a second.
-
1:58 - 2:00Once you actually get a tornado,
-
2:00 - 2:01again, the problem that we have
-
2:01 - 2:03is getting measurements near the surface.
-
2:03 - 2:05It's really hard to get measurements near the surface
-
2:05 - 2:08because most people don't want to drive into tornadoes.
-
2:08 - 2:10There are a few exceptions,
-
2:10 - 2:12and you might have seen them on TV shows.
-
2:12 - 2:13But most people don't want to do that.
-
2:13 - 2:17And even getting instrumentation in the path of the tornado is pretty tricky, too.
-
2:17 - 2:19Because, again, you don't want to be that close to a tornado
-
2:19 - 2:23because sometimes the winds around the tornado are strong, as well.
-
2:23 - 2:27So, getting information, that critical location, is key for us.
-
2:27 - 2:28Because, again, we don't know
-
2:28 - 2:30if the winds that we're seeing above ground level,
-
2:30 - 2:31way above building level,
-
2:31 - 2:33actually map to the surface.
-
2:33 - 2:34If they're stronger, if they're weaker,
-
2:34 - 2:38or if they're about the same as what we're saying above buildings.
-
2:38 - 2:39The way that we get at answering a lot of these questions,
-
2:39 - 2:42and I'm an observationalist, so I love to get out in the field,
-
2:42 - 2:44I love to collect data on tornadoes,
-
2:44 - 2:45we compile a lot of observations.
-
2:45 - 2:48And I work with this group who operates these mobile radars,
-
2:48 - 2:49and they're exactly what they say they are:
-
2:49 - 2:52they're basically a radar on the back of a big blue truck,
-
2:52 - 2:54and we drive up really close to tornadoes
-
2:54 - 2:57to map out the winds, we map out the precipitation,
-
2:57 - 2:59we map out all these different things that are going on
-
2:59 - 3:03in order to better understand the processes in these storms.
-
3:03 - 3:04And that bottom there,
-
3:04 - 3:06that's what a tornado looks like
-
3:06 - 3:07when you're looking at it with a mobile radar
-
3:07 - 3:09and when you're looking at it with a mobile radar really close.
-
3:09 - 3:11Also, what we do is we do a lot of modeling,
-
3:11 - 3:14so we do a lot of computer models and simulations
-
3:14 - 3:17because the atmosphere is governed by the laws of physics,
-
3:17 - 3:19so we can model the laws of physics
-
3:19 - 3:21and see where the tornado might go,
-
3:21 - 3:22where the storm might go,
-
3:22 - 3:24how strong the winds are near the surface
-
3:24 - 3:26and not actually have to go out in the field.
-
3:26 - 3:29But, of course, we want to have both observations and modelling
-
3:29 - 3:31to move forward with the science.
-
3:31 - 3:35So, this is, I showed you that video earlier that went real quick, too.
-
3:35 - 3:37This is what it looks like when you're looking at it with a radar.
-
3:37 - 3:38So you saw it visually,
-
3:38 - 3:40but this is what I get really excited about
-
3:40 - 3:41when I see now in the field
-
3:41 - 3:42is stuff that looks like this.
-
3:42 - 3:45And the really exciting thing about looking at stuff like this
-
3:45 - 3:46is that this storm,
-
3:46 - 3:49we caught it from when it didn't make a tornado
-
3:49 - 3:50to when it made a tornado
-
3:50 - 3:51and it intensified
-
3:51 - 3:52and when it dissipated.
-
3:52 - 3:54So, this is the one of the really rare data sets
-
3:54 - 3:55that we have out there
-
3:55 - 3:59that we're able to study the entire life cycle of a tornado.
-
3:59 - 4:00I talked about that rear-flying down draft,
-
4:00 - 4:02how we think that rear flanking downdraft is important
-
4:02 - 4:05because it tilts, there's a lot of spin in the atmosphere,
-
4:05 - 4:07but the problem with all this spin in the atmosphere
-
4:07 - 4:10is it needs to be oriented vertically
-
4:10 - 4:11because that's what tornadoes are doing,
-
4:11 - 4:14and it needs to orientated vertically near the ground.
-
4:14 - 4:17So, we think this rear flanking downdraft, we think that it just pulses.
-
4:17 - 4:19And these pulses in this rear flanking downdraft,
-
4:19 - 4:20we think are very important
-
4:20 - 4:22for converging that rotation
-
4:22 - 4:25but also getting that rotation into the right place.
-
4:25 - 4:26Other things that we've learned
-
4:26 - 4:29is that we have gotten a bunch of fortuitous measurements
-
4:29 - 4:30in the path of the tornadoes
-
4:30 - 4:31and very near the surface.
-
4:31 - 4:34And we found out that the winds near the surface
-
4:34 - 4:36are actually pretty comparable
-
4:36 - 4:39to what we're seeing 30, 40 meters above ground level.
-
4:39 - 4:42So there's not a big reduction in what we're seeing above the surface
-
4:42 - 4:44to what we're seeing at house level.
-
4:44 - 4:46And that was a pretty surprising finding for us
-
4:46 - 4:48because we kind of assumed that
-
4:48 - 4:51the winds decreased pretty substantially near the surface.
-
4:51 - 4:52So I'm going to end it with this real quick.
-
4:52 - 4:55And this is not my last tornado I ever saw,
-
4:55 - 4:57but I really like this image
-
4:57 - 5:00because this was taken with one of those mobile radars I was talking about.
-
5:00 - 5:01And this is a tornado, not a hurricane,
-
5:01 - 5:03and this is what it looks like
-
5:03 - 5:04when you're really close to it.
-
5:04 - 5:05And I find this amazing,
-
5:05 - 5:07that we can actually take technology,
-
5:07 - 5:09take technology this close to these types of storms,
-
5:09 - 5:11and see these inner workings.
-
5:11 - 5:14And for those of you who look at tornado images often,
-
5:14 - 5:16you can see there's a lot going on there.
-
5:16 - 5:18There's rain spiraling, and you can actually see the debris cloud
-
5:18 - 5:20associated with this tornado,
-
5:20 - 5:22and I look forward to the future and future technologies
-
5:22 - 5:25and being able to learn a lot more about these storms
-
5:25 - 5:27as the world advances,
-
5:27 - 5:28as you guys contribute to the science,
-
5:28 - 5:31and we're able to really learn more about how tornadoes form.
-
5:31 - 5:34Thank you!
- Title:
- How to track a tornado - Karen Kosiba
- Description:
-
View full lesson: http://ed.ted.com/lessons/how-to-track-a-tornado-karen-kosiba
Atmospheric scientist Karen Kosiba studies how tornadoes form and do damage. Getting measurements near the surface of these twisters is difficult, though, and driving into them is a practice mostly reserved for the big screen. In this TEDYouth Talk, Kosiba describes how she and her team use observations and modeling to track these super storms, while sharing some incredible footage from the field.
Talk by Karen Kosiba.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 05:45
Krystian Aparta commented on English subtitles for How to track a tornado - Karen Kosiba | ||
Krystian Aparta edited English subtitles for How to track a tornado - Karen Kosiba | ||
Jessica Ruby edited English subtitles for How to track a tornado - Karen Kosiba | ||
Caroline Cristal approved English subtitles for How to track a tornado - Karen Kosiba | ||
Caroline Cristal edited English subtitles for How to track a tornado - Karen Kosiba | ||
Caroline Cristal edited English subtitles for How to track a tornado - Karen Kosiba | ||
Madeleine Aronson accepted English subtitles for How to track a tornado - Karen Kosiba | ||
Caroline Cristal approved English subtitles for How to track a tornado - Karen Kosiba |
Krystian Aparta
The English transcript was updated on 2/19/2016.