How do tornadoes form? - James Spann

Kako se formiraju tornada? - Džejms Spen (James Spann)

Prevodilac: Tijana Mihajlović Lektor: Mile Živković

They call me the tornado chaser.

Zovu me lovac na tornada.

When the wind is up and conditions are right,

Kada se vetar podigne i stvore se uslovi,

I get in my car and follow violent storms.

ulazim u svoj auto i pratim silovite oluje.

"Crazy," you say? Perhaps, but really I chase these sky beasts to learn about them.

„Ludo", kažete? Možda, ali jurim te nebeske zveri da bih učio o njima.

I want to share with you what I know.

Želim da podelim sa vama ono što znam.

Tornadoes are rapidly rotating columns of air that form inside storms

Tornada su brzorotirajući stubovi vazduha koji se formiraju unutar oluje

that connect with the ground via a funnel of cloud.

i povezuju sa zemljom preko levka oblaka.

When that happens, they tear across the Earth,

Kada se to desi, oni razaraju po površini Zemlje,

posing a huge threat to life and property.

predstavljajući veliku pretnju životu i imovini.

Because of this, there's a great deal of research into these phenomena,

Zbog ovoga, postoje velika istraživanja ove pojave,

but the truth is, there's still a lot we don't know about how tornadoes form.

ali istina je da još uvek ne znamo kako se tornada formiraju.

The conditions that may give rise to one tornado

Uslovi zbog kojih se stvara jedan tornado

won't necessarily cause another.

ne moraju obavezno izazvati i drugi.

But we have learned a lot since people first started recording tornadoes,

Međutim, naučili smo dosta od kada su ljudi počeli da snimaju tornada,

like how to recognize the signs when one is brewing in the sky.

kao što je kako da prepoznamo znake kada se tornado komeša na nebu.

Are you coming along for the ride?

Da li hoćete da se pridružite vožnji?

Tornadoes begin with a thunderstorm but not just any thunderstorm.

Tornado počinje grmljavinom, ali ne običnom.

These are especially powerful, towering thunderstorms called supercells.

To su posebno snažne, izuzetno visoke grmljavine koje se nazivaju super-oluje.

Reaching up to over 50,000 feet, they bring high force winds,

Dostižu i do 60 kilometara visine i donose veoma snažne vetrove,

giant hailstones, sometimes flooding and great flashes of lightning, too.

snažan grad, ponekad ogromnu kišu i intenzivno sevanje munja.

These are the kinds of storms that breed tornadoes,

Ovo su oluje koje stvaraju tornado,

but only if there are also very specific conditions in place,

ali samo ako postoje specifični uslovi,

clues that we can measure and look out for when we're trying to forecast a storm.

tragovi koje možemo izmeriti i potražiti kada pokušavamo da predvidimo oluju.

Rising air is the first ingredient needed for a tornado to develop.

Vazduh koji se podiže je prvi sastojak koji je potreban da se tornado razvije.

Any storm is formed when condensation occurs,

Svaka oluja se formira kada se pojavi kondenzacija,

the byproducts of the clouds.

nuspojava oblaka.

Condensation releases heat,

Kondenzacija ispušta toplotu,

and heat becomes the energy that drives huge upward drafts of air.

a toplota postaje energija koja pokreće ogromne vazdušne struje naviše.

The more condensation and the bigger the storm clouds grow,

Što je kondenzacija veća i što više rastu olujni oblaci,

the more powerful those updrafts become.

vazdušne struje postaju snažnije.

In supercells, this rising airmass is particularly strong.

U super-olujama, ova masa vazduha koja se podiže je posebno snažna.

As the air climbs, it can change direction and start to move more quickly.

Dok se penje, vazduh može da promeni pravac i da počne brže da se kreće.

Finally, at the storm's base, if there is a lot of moisture,

Konačno, u osnovi oluje, ako postoji mnogo vlage,

a huge cloud base develops, giving the tornado

razvija se ogromna baza oblaka,

something to feed off later, if it gets that far.

dajući tornadu nešto čemu će se vratiti ako stigne dotle.

When all these things are in place, a vortex can develop enclosed by the storm,

Kada se sve ove stvari pojave,

vrtlog može da se razvije uz oluju,

and forming a wide, tall tube of spinning air that then gets pulled upwards.

kao i formiranje široke,

visoke cevi uskovitlanog vazduha

koji onda biva povučen naviše.

We call this a mesocyclone.

Ovo zovemo mezociklon.

Outside, cool, dry, sinking air

Spoljašnji, hladni, suvi, ponirući vazduh

starts to wrap around the back of this mesocyclone,

počinje da se obavija oko spoljašnosti ovog mezociklona,

forming what's known as a rear flank downdraft.

formirajući nešto što je poznato kao zadnji bok silazne struje.

This unusual scenario creates a stark temperature difference

Ovaj neobični scenario stvara krajnju temperaturnu razliku

between the air inside the mesocyclone, and the air outside,

između unutrašnjeg vazduha mezociklona i spoljašnjeg vazduha,

building up a level of instability that allows a tornado to thrive.

gradeći nivo nestabilnosti koji dozvoljava tornadu da nabuja.

Then, the mesocyclone's lower part becomes tighter,

Zatim, niži deo mezociklona postaje jači,

increasing the speed of the wind.

povećavajući brzinu vetra.

If, and that's a big if, this funnel of air moves down

Ako, a to je veliko „ako", levak vazduha krene naniže

into that large, moist cloud base at the bottom of the parent storm,

u tu ogromnu, vlažnu osnovu oblaka na dnu matične oluje,

it sucks it in and turns it into a rotating wall of cloud,

biva uvučen unutra i pretvara se u rotirajući zid oblaka,

forming a link between the storm that created it and the Earth.

formirajući vezu između oluje koja ga je stvorila i zemlje.

The second that tube of spinning cloud touches the ground,

U trenutku kada ta cev uskomešanog oblaka

it becomes a tornado.

dodirne zemlju, postaje tornado.

Most are small and short-lived, producing winds of 65-110 miles per hour,

Većinom su mali i kratkotrajni, a proizvode vetrove od 105 - 177 km/h,

but others can last for over an hour, producing 200 mile per hour winds.

ali mogu trajati i više od sat vremena, stvarajući vetrove od 320 km/h.

They are beautiful but terrifying,

Lepi su, ali zastrašujući,

especially if you or your town is in its path.

posebno ako ste im vi ili vaš grad na putu.

In that case, no one, not even tornado chasers like me,

U tom slučaju niko, čak ni lovci na tornada kao ja,

enjoy watching thing unfold.

ne uživa u pogledu na njihovo širenje.

Just like everything, however, tornadoes do come to an end.

Kao i sve ostalo, međutim, tornada prođu.

When the temperature difference disappears and conditions grow more stable,

Kada temperaturne razlike nestanu, a uslovi postanu stabilniji,

or the moisture in the air dries up,

ili se vlaga iz vazduha isuši,

the once fierce parent storm loses momentum and draws its tornado back inside.

nekada žestoka matična oluja izgubi zamah i povuče svoj tornado unutra.

Even so, meteorologists and storm chasers like me will remain on the lookout,

Čak i tada, meteorolozi i lovci na tornada kao što sam ja ostaće na oprezu,

watching, always watching to see if the storm releases its long rope again.

posmatrajući, uvek gledajući da vide ako oluja opet oslobodi svoje dugo uže.