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 tornado shot.
-
0:13 - 0:15Alright, that was the first tornado I ever saw,
-
0:15 - 0:16and it was really cool,
-
0:16 - 0:17and it was really scary,
-
0:17 - 0:18and the reason I'm showing it to you guys
-
0:18 - 0:20was because that's why I got into the field
-
0:20 - 0:21in the first place.
-
0:21 - 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 Vortex 2,
-
0:32 - 0:34where myself and a bunch of other scientists
-
0:34 - 0:35were out there
-
0:35 - 0:36surrounding tornadoes with different types of instrumentation
-
0:36 - 0:40and trying to figure out how tornadoes form.
-
0:40 - 0:41So, it's a big question
-
0:41 - 0:42that we're trying to answer.
-
0:42 - 0:43It sounds like a basic one,
-
0:43 - 0:45but it's something 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 - 0:53but we really don't know what the winds are like
-
0:53 - 0:54at the surface
-
0:54 - 0:56and how that relates
-
0:56 - 0:57to 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 - 1:04are what you commonly think of as
-
1:04 - 1:06tornado-racing storms.
-
1:06 - 1:07They're big, rotating thunderstorms
-
1:07 - 1:10that happen a lot in the mid section of the United States.
-
1:10 - 1:12But the problem is
-
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 - 1:19and when we look at these pictures
-
1:19 - 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 - 1:25if we're trying to make tornado forecasts or tornado warnings
-
1:25 - 1:27because we only want to warn on the storms
-
1:27 - 1:29or forecast on the storms
-
1:29 - 1:31that are going to actually make a tornado.
-
1:31 - 1:34One of the big critical distinguishing features
-
1:34 - 1:35that we think between these storms
-
1:35 - 1:38is something about the rear flank down draft.
-
1:38 - 1:39So, these big rotating thunderstorms
-
1:39 - 1:43have this down draft that wraps around the rear edge of it,
-
1:43 - 1:44hence the rear-flanking down draft.
-
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 - 2:02again, the problem that we have
-
2:02 - 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 - 2:16And even getting instrumentation in the path of the tornado
-
2:16 - 2:17is pretty tricky, too
-
2:17 - 2:20because, again, you don't want to be that close to a tornado
-
2:20 - 2:23because sometimes the winds around the tornado are strong, as well.
-
2:23 - 2:24So, getting information,
-
2:24 - 2:26that critical location,
-
2:26 - 2:27is 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 - 2:50and they're exactly what they say they are:
-
2:50 - 2:51they're basically a radar on the back
-
2:51 - 2:52of a big blue truck,
-
2:52 - 2:54and we drive up really close to tornadoes
-
2:54 - 2:56to map out the winds, we map out the precipitation,
-
2:56 - 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 - 3:10and when you're looking at it with a mobile radar real close.
-
3:10 - 3:11Also, we do a lot of modelling,
-
3:11 - 3:14so we do a lot of computer models and simulations
-
3:14 - 3:16because the atmosphere is governed by the laws of physics,
-
3:16 - 3:19so we can model the laws of physics
-
3:19 - 3:21and see where the tornado might go,
-
3:21 - 3:23where the storm might go,
-
3:23 - 3:24how strong the winds are near the surface
-
3:24 - 3:26and not actually have to go out in the field.
-
3:26 - 3:28But, of course, we want to have both
-
3:28 - 3:29observations and modelling
-
3:29 - 3:31to move forward with the science.
-
3:31 - 3:32So, this is,
-
3:32 - 3:33we showed you that video earlier
-
3:33 - 3:35that went real quick, too.
-
3:35 - 3:37This is what it looks like when you look 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 - 3:43is stuff like this.
-
3:43 - 3:44And the really exciting thing about
-
3:44 - 3:45looking at stuff like this
-
3:45 - 3:47is that this storm,
-
3:47 - 3:49we caught it from when it didn't make a tornado
-
3:49 - 3:50to when it made a tornado
-
3:50 - 3:51to when it intensified
-
3:51 - 3:52to when it disappeared.
-
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-flying down draft is important
-
4:02 - 4:06because it tilts, there's a lot of spin in the atmosphere,
-
4:06 - 4:08but the problem with all this spin in the atmosphere
-
4:08 - 4:10is it needs to be oriented vertically
-
4:10 - 4:11because that's what tornadoes are doing,
-
4:11 - 4:13and it needs to orientated vertically
-
4:13 - 4:14near the ground.
-
4:14 - 4:15So, we think this rear-flying downdraft,
-
4:15 - 4:17we think that it just pulses,
-
4:17 - 4:19and these pulses in this rear-flying draft,
-
4:19 - 4:20we think are very important
-
4:20 - 4:22for converging that rotation
-
4:22 - 4:24and also getting that rotation in the right place.
-
4:24 - 4:26Other things that we've learned
-
4:26 - 4:28is that we have gotten a bunch of fortuitous measurements
-
4:28 - 4:30in the path of the tornadoes
-
4:30 - 4:32and very near the surface.
-
4:32 - 4:33And we found out that the winds near the surface
-
4:33 - 4:35are actually pretty comparable
-
4:35 - 4:38to what we're seeing 30 to 40 meters above ground level,
-
4:38 - 4:41so there's not a big reduction in what we're seeing
-
4:41 - 4:44above the surface to what we're seeing at house level.
-
4:44 - 4:45And that was a pretty surprising finding for us
-
4:45 - 4:47because we kind of assumed
-
4:47 - 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 - 4:55This is not the last tornado I ever saw,
-
4:55 - 4:57but I really like this image
-
4:57 - 4:59because it was taken with one of those mobile radars I was talking about.
-
4:59 - 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 - 5:06And I find this amazing,
-
5:06 - 5:07that we can actually take technology,
-
5:07 - 5:09take technology this close to these types of storms,
-
5:09 - 5:11and see this 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 - 5:17There's rain spiraling,
-
5:17 - 5:19and you can actually see the debris cloud
-
5:19 - 5:20associated with this tornado,
-
5:20 - 5:22and I look forward to the future
-
5:22 - 5:23and future technologies
-
5:23 - 5:24and being able to learn a lot more about these storms
-
5:24 - 5:27as the world advances
-
5:27 - 5:28and you guys contribute to the science
-
5:28 - 5:31and we're able to really learn how tornadoes form.
-
5:31 - 5:32Thank 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.