神话传说里充满各种奇幻而具有毁灭性的生物。在现实中，我们遇到的灾难往往是由自然或人为因素造成的。在这个世界上，很少有其他毁灭性的力量像龙卷风这个怪兽这么形态独特、穷凶极恶。这些风暴就像从云层中伸出的匕首，摩天大楼在它们面前也相形见绌。而在鞭打大地之时，它们似乎心怀怨恨，誓要将周遭的一切吞没。
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.
它们被称为旋风或龙卷风，是自然界最暴虐的风暴，其风力最高可达每小时300英里（约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.
每年美国约有800个旋风，比世界上其他地方都多。受灾最严重的地区是从德克萨斯州到南达科他州之间的大平原带，该地区被称为“龙卷风走廊”。每当春夏，热空气从墨西哥湾上升，在这里与从加拿大南下的冷空气交锋，从而产生叫做“超级单体”的强雷暴。科学家尚未完全清楚龙卷风是何时以及如何形成的，但他们知道，在合适的条件下，一个这样的超级单体风暴可以形成龙卷风。
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.
暖湿空气流入风暴以后便会抬升，并受到上层气流的影响而扭曲。随着这条旋转空气柱的力量逐渐加强，下部发生冲撞的条件也成熟了。当受到雨水冷却的下沉气流碰上地面附近的暖空气时，超级单体下方就会形成一种在低空旋转的云。这时，龙卷风一触即发。
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.
龙卷风持续的时间不长——从20秒到一个小时不等——但其带来的破坏则需要数年才能恢复。在美国，这种风暴每年导致约90人丧生，带来数百万美元的损失。发现龙卷风时，专家建议人们躲入地下室，远离窗户，或者爬入一楼的浴缸避险。
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.
遇上龙卷风时，大多数人为求安全都对它避之则吉，有些科学家却偏向虎山行。这些追风者追猎龙卷风，试图追寻风暴的路径。他们会遇到令人难以置信的云层运动、暴雨、强风和冰雹、闪电，以及叹为观止的风暴结构。当他们最终确定一个龙卷风的位置时，便用特殊工具进行测量。他们希望有一天能够精确预测龙卷风将在何时袭击哪个地方。
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.
虽然几乎没有什么能够预防龙卷风造成的破坏，但若能做到更好的预报，则可以拯救更多生命，让幸存者们在逃过地球上最猛烈风暴的袭击之后得以重建家园。
Storm Chasers
追风者
Everybody has a passion for something. It just so happens that mine is chasing tornados.
每个人都有爱好，只不过我的爱好恰好是追逐龙卷风罢了。
Scientist: Let’s go. Let’s go. It’s got one more.
科学家：走吧，走吧，还有一个呢。
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·萨马拉斯，在一家叫“应用研究协会”的公司工作，是一名高级工程师。实际上，通过开发这些探测器，我得以将我的工程学背景和追逐风暴的爱好结合起来。现在我可以出去做自己喜欢的事情了。每个人都应该追随自己的爱好，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.
这些探测器很精密。此外还有一些用来测量龙卷风的其他设备，比如多普勒雷达，但它们只能测量龙卷风上部的情况。还没有人真正钻进龙卷风底部看看那里的情况，那里才是龙卷风真正造成破坏的部分——就在从地面往上大约30英尺（9米）处。正是这一部分破坏房屋，将汽车抛上半空，造成人员伤亡。
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.
掌握或设计出最好的技术对于我要做的事很重要。身处龙卷风的路径时，你只有一次机会。设备必须能够运转，而且是正确地运转。
On June 24th, 2003, we were in southeast South Dakota.
2003年6月24日，我们正在南达科他州的东南部。
Broadcast: This is a dangerous storm. Take 23)shelter immediately.
广播：这是一场危险的风暴，请马上避难。
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.
我们在雨中行驶，我正在使用全球定位系统。后来雨停了，汽车的雨刷拂去最后几滴雨。这时，龙卷风这头巨兽赫然显现在我们面前。
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.
我们只在它的路径上稍作停留。当我们出来的时候，我们能……我们能听到龙卷风的声音。那几乎是一种震耳欲聋的咆哮，听起来就像一个由喷气式引擎启动的瀑布。奔赴现场，亲眼目睹这个情景——看着大自然母亲慢慢揭开面纱——而你不知道接下来会发生什么情况。风暴会继续加强吗？你一无所知。但是我必须尽量接近龙卷风，以便通过我所用的工具获取最准确的读数。
We were just a half a mile west of Manchester.
我们正在距离曼彻斯特以西一英里（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.
龙卷风在曼彻斯特肆虐，城西一处房屋正好位于其外沿。我想当时龙卷风可能只用了五秒或者十秒就把那座房子完全毁坏，夷为平地。
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.
我们通过探测器收集到的这些数据就像是我带回来的拼图碎片，它们能帮助我们理解龙卷风的一些动力学原理。这对农民意味着什么？或许能帮他们赢得少许间隔时间。但更为重要的是，如果我们能充分理解那些数据，或许我们就可以对房屋建造进行改进。或许我们可以让屋顶坚持久一点；假如我们能使屋顶坚守多一会儿，人们逃生的可能性就会更高。我希望这些数据能得到很好的运用。事实上它们已经得到善用，已经是这样了。
