自然界最強(qiáng)風(fēng)暴——龍卷風(fēng) Tornados——Nature’s Ultimate Storms
Call them twisters or tornados; they’re nature’s most violent storms, with 1)swirling winds that can top 300 miles per hour.
它們被稱為旋風(fēng)或龍卷風(fēng)，是自然界最暴虐的風(fēng)暴，其風(fēng)力最高可達(dá)每小時300英里(約483千米)。
About 800 twisters 2)sweep through the US every year, more than anywhere else in the world. The hardest hit area is a 3)swath of the great plains from Texas to South Dakota, known as “Tornado 4)Alley.” Here, warm air flows up from the Gulf of Mexico in the spring and summer and 5)crashes into cold air pushing down from Canada. The meeting produces violent thunderstorms called “supercells.” Scientists don’t completely understand how or when tornados form, but they do know a supercell like this one can produce a twister if the conditions are right.
每年美國約有800個旋風(fēng)，比世界上其他地方都多。受災(zāi)最嚴(yán)重的地區(qū)是從德克薩斯州到南達(dá)科他州之間的大平原帶，該地區(qū)被稱為“龍卷風(fēng)走廊”。每當(dāng)春夏，熱空氣從墨西哥灣上升，在這里與從加拿大南下的冷空氣交鋒，從而產(chǎn)生叫做“超 級單體”的強(qiáng)雷暴�？茖W(xué)家尚未完全清楚龍卷風(fēng)是何時以及如何形成的，但他們知道，在合適的條件下，一個這樣的超 級單體風(fēng)暴可以形成龍卷風(fēng)。
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As warm, 6)moist air flows into a storm, it gets pushed up and 7)twisted by upper level winds. As this 8)rotating 9)column of air gathers force, conditions are right for a 10)collision below. When rain-cooled 11)downdrafts hit warm air near the ground, a low-hanging 12)revolving cloud forms beneath the cell: A tornado is 13)imminent.
暖濕空氣流入風(fēng)暴以后便會抬升，并受到上層氣流的影響而扭曲。隨著這條旋轉(zhuǎn)空氣柱的力量逐漸加強(qiáng)，下部發(fā)生沖撞的條件也成熟了。當(dāng)受到雨水冷卻的下沉氣流碰上地面附近的暖空氣時，超 級單體下方就會形成一種在低空旋轉(zhuǎn)的云。這時，龍卷風(fēng)一觸即發(fā)。
Tornados don’t last long—anywhere from 20 seconds to an hour, but it can take years to recover from the devastation. These storms kill nearly 90 people each year in the US and cause millions of dollars worth of damage. When a tornado is spotted, experts advise going to a basement, staying away from any windows, or climbing into a first-floor 14)bathtub.
龍卷風(fēng)持續(xù)的時間不長——從20秒到一個小時不等——但其帶來的破壞則需要數(shù)年才能恢復(fù)。在美國，這種風(fēng)暴每年導(dǎo)致約90人喪生，帶來數(shù)百萬美元的損失。發(fā)現(xiàn)龍卷風(fēng)時，專家建議人們躲入地下室，遠(yuǎn)離窗戶，或者爬入一樓的浴缸避險。
While most people run for safety when a twister appears, some scientists actually race to meet it. These storm chasers hunt down tornados trying to get right in the twister’s path. They 15)encounter incredible cloud movement, 16)torrential rain, 17)severe winds and 18)hail, lightning, and breathtaking storm structures. When they finally locate a twister, they measure it using special tools. These scientists hope to, someday, predict exactly when and where tornados will strike.
遇上龍卷風(fēng)時，大多數(shù)人為求安全都對它避之則吉，有些科學(xué)家卻偏向虎山行。這些追風(fēng)者追獵龍卷風(fēng)，試圖追尋風(fēng)暴的路徑。他們會遇到令人難以置信的云層運(yùn)動、暴雨、強(qiáng)風(fēng)和冰雹、閃電，以及嘆為觀止的風(fēng)暴結(jié)構(gòu)。當(dāng)他們最終確定一個龍卷風(fēng)的位置時，便用特殊工具進(jìn)行測量。他們希望有一天能夠精確預(yù)測龍卷風(fēng)將在何時襲擊哪個地方。
Little can prevent the damage caused by tornados, but better forecasting could save more lives, giving survivors the chance to rebuild after living through one of the most violent storms on earth.
雖然幾乎沒有什么能夠預(yù)防龍卷風(fēng)造成的破壞，但若能做到更好的預(yù)報，則可以拯救更多生命，讓幸存者們在逃過地球上最猛烈風(fēng)暴的襲擊之后得以重建家園。
Storm Chasers
追風(fēng)者
Everybody has a passion for something. It just so happens that mine is chasing tornados.
每個人都有愛好，只不過我的愛好恰好是追逐龍卷風(fēng)罷了。
Scientist: Let’s go. Let’s go. It’s got one more.
科學(xué)家：走吧，走吧，還有一個呢。
My name is Tim Samaras. I work for a company called 19)Applied Research 20)Associates. I’m a senior engineer. By me developing these 21)probes, I was actually able to mix my engineering background with my storm chasing. Now I get to go out and follow my passion. And everybody should follow their passions; they really should.
我叫蒂姆·薩馬拉斯，在一家叫“應(yīng)用研究協(xié)會”的公司工作，是一名高級工程師。實(shí)際上，通過開發(fā)這些探測器，我得以將我的工程學(xué)背景和追逐風(fēng)暴的愛好結(jié)合起來。現(xiàn)在我可以出去做自己喜歡的事情了。每個人都應(yīng)該追隨自己的愛好，真的。
These probes are very sophisticated. There’s some other equipment out there that measures the tornados, such as the 22)Doppler radar. They only measure the upper part of the tornado. Nobody has really gotten down and looked at the bottom part of the tornado where it really does the damage; say from the ground up to 30 feet. That’s where all the houses get destroyed or cars get picked up and lives are lost.
這些探測器很精密。此外還有一些用來測量龍卷風(fēng)的其他設(shè)備，比如多普勒雷達(dá)，但它們只能測量龍卷風(fēng)上部的情況。還沒有人真正鉆進(jìn)龍卷風(fēng)底部看看那里的情況，那里才是龍卷風(fēng)真正造成破壞的部分——就在從地面往上大約30英尺(9米)處。正是這一部分破壞房屋，將汽車拋上半空，造成人員傷亡。
I think it’s very important to have the best technology I can get or design to do what I have to do. You only get one chance when you’re in the path of the tornado. The equipment has to work and it has to work correctly.
掌握或設(shè)計(jì)出最好的技術(shù)對于我要做的事很重要。身處龍卷風(fēng)的路徑時，你只有一次機(jī)會。設(shè)備必須能夠運(yùn)轉(zhuǎn)，而且是正確地運(yùn)轉(zhuǎn)。
On June 24th, 2003, we were in southeast South Dakota.
2003年6月24日，我們正在南達(dá)科他州的東南部。
Broadcast: This is a dangerous storm. Take 23)shelter immediately.
廣播：這是一場危險的風(fēng)暴，請馬上避難。
We were driving through rain. I was using GPS注. And then, when the rain stopped and the 24)wipers 25)flicked off the last few drops of rain, this beast of a tornado just appeared.
我們在雨中行駛，我正在使用全球定位系統(tǒng)。后來雨停了，汽車的雨刷拂去最后幾滴雨。這時，龍卷風(fēng)這頭巨獸赫然顯現(xiàn)在我們面前。
We stopped in its path very briefly. When we got out, we could…we could hear the tornado; it was nearly a 26)deafening 27)roar. It sounded like a waterfall powered by a jet engine. To be there and watch this thing—watch mother nature 28)unfolding—and you don’t know what it’s going to do. Is it going to continue to grow? You just don’t know. But, I have to get close to a tornado, so that I can get the best readings that I can with the tools I have.
我們只在它的路徑上稍作停留。當(dāng)我們出來的時候，我們能……我們能聽到龍卷風(fēng)的聲音。那幾乎是一種震耳欲聾的咆哮，聽起來就像一個由噴氣式引擎啟動的瀑布。奔赴現(xiàn)場，親眼目睹這個情景——看著大自然母親慢慢揭開面紗——而你不知道接下來會發(fā)生什么情況。風(fēng)暴會繼續(xù)加強(qiáng)嗎?你一無所知。但是我必須盡量接近龍卷風(fēng)，以便通過我所用的工具獲取最準(zhǔn)確的讀數(shù)。
We were just a half a mile west of Manchester.
我們正在距離曼徹斯特以西一英里(1.6千米)的地方。
And, as the tornado 29)tore through Manchester, there was a house on the west side of town that got caught on the outer edge of the tornado. I’m thinking it probably took five seconds, maybe ten seconds for that tornado to completely destroy that house and wipe it clean.
龍卷風(fēng)在曼徹斯特肆虐，城西一處房屋正好位于其外沿。我想當(dāng)時龍卷風(fēng)可能只用了五秒或者十秒就把那座房子完全毀壞，夷為平地。
The pieces of the puzzle that I bring, by the data we collect in the probes, helps us understand some of the 30)dynamics of tornados. And what that means to the farmers? Maybe a little extra 31)lead time. But more importantly, if we knew a lot of that data, maybe we can improve on building of a house. Maybe we can keep the roof on just a little bit longer, and if we keep the roof on a little longer, then chances of survival are much higher. I’m hoping that some of this data will be put to good use. It already has. It already has.
我們通過探測器收集到的這些數(shù)據(jù)就像是我?guī)Щ貋淼钠磮D碎片，它們能幫助我們理解龍卷風(fēng)的一些動力學(xué)原理。這對農(nóng)民意味著什么?或許能幫他們贏得少許間隔時間。但更為重要的是，如果我們能充分理解那些數(shù)據(jù)，或許我們就可以對房屋建造進(jìn)行改進(jìn)。或許我們可以讓屋頂堅(jiān)持久一點(diǎn);假如我們能使屋頂堅(jiān)守多一會兒，人們逃生的可能性就會更高。我希望這些數(shù)據(jù)能得到很好的運(yùn)用。事實(shí)上它們已經(jīng)得到善用，已經(jīng)是這樣了。
資料來源考試網(wǎng)校老師主講教材精講班課程，完整講義下載進(jìn)入個人中心>>
