Name: 【TED-Ed】How to track a tornado - Karen Kosiba
Uploaded: 2015-01-24T02:33:17.000Z
Duration: 5 min 45 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

need to start with an awesome tornado shot.

And this is not that awesome tornado shot.

Alright, that was the first tornado I ever saw,

and the reason I'm showing it to you guys

was because that's why I got into the field in the first place.

it was really cool to be out there the first time.

where myself and a bunch of other scientists were out there

surrounding tornadoes with different types of instrumentation

and trying to figure out how tornadoes form.

So, it's a big question that we're trying to answer.

but it's something that we're still trying to figure out.

what the winds are like near the surface.

We know what the winds are like above building level,

but we really don't know what the winds are like at the surface

and how that relates to what we're seeing above building level.

So, most tornadoes form from what we call supercell thunderstorms,

are what you commonly think of as tornado-raising storms.

that happen a lot of times in the midsection of the United States.

doesn't mean they're rotating at the surface.

and when we look at the data that we have

if we're trying to make tornado forecasts or tornado warnings

because we only want to warn on the storms

that are going to actually make a tornado.

One of the big critical distinguishing features

is something about the rear flank downdraft.

have this downdraft that wraps around the rear edge of it,

And there's certainly a lot more that goes into it

and I'll tell you a little more about that in a second.

is getting measurements near the surface.

It's really hard to get measurements near the surface

because most people don't want to drive into tornadoes.

and you might have seen them on TV shows.

And even getting instrumentation in the path of the tornado is pretty tricky, too.

Because, again, you don't want to be that close to a tornado

because sometimes the winds around the tornado are strong, as well.

So, getting information, that critical location, is key for us.

if the winds that we're seeing above ground level,

or if they're about the same as what we're saying above buildings.

The way that we get at answering a lot of these questions,

and I'm an observationalist, so I love to get out in the field,

And I work with this group who operates these mobile radars,

and they're exactly what they say they are:

they're basically a radar on the back of a big blue truck,

and we drive up really close to tornadoes

to map out the winds, we map out the precipitation,

we map out all these different things that are going on

in order to better understand the processes in these storms.

when you're looking at it with a mobile radar

and when you're looking at it with a mobile radar really close.

Also, what we do is we do a lot of modeling,

so we do a lot of computer models and simulations

because the atmosphere is governed by the laws of physics,

how strong the winds are near the surface

and not actually have to go out in the field.

But, of course, we want to have both observations and modelling

So, this is, I showed you that video earlier that went real quick, too.

This is what it looks like when you're looking at it with a radar.