科学美国人60秒 SSS 沐浴雨中 随风飘荡（在线收听）

Back in January, one of California's oldest and most iconic residents keeled over: the Pioneer Cabin tree, a giant sequoia in Calaveras Big Trees State Park…so big you used to be able to drive through it.

在今年一月份，加州一座最古老、最具特色的标志倒了：先锋小屋树，这是位于卡拉维拉斯州立公园一颗巨大的红杉……这个红杉形成的树洞非常的大，你可以开车通过。

The giant was blown over by high winds—delivered by what’s called an atmospheric river, a long stream of water vapor in the atmosphere, 100 miles wide. These systems might be thought of as some of the biggest rivers on Earth.

这个巨大的红杉，是被大气层河流所形成的强风刮到的。大气层河流是大气层中的巨大湿空气带(约100英里宽)。人们认为大气层河流是地球上最大的河流之一。

"You could kind of pose it that way, yeah." Duane Waliser, an atmospheric scientist at the Jet Propulsion Lab. "An atmospheric river will carry the same amount of water vapor as, say, 15 to 20 Mississippi Rivers."

“可以这样类比。”Duane Waliser是喷气推进实验室的大气科学家。“大气层河流所携带的水蒸汽的总量约相当于15-20个密西西比河。”

Waliser and his JPL colleague Bin Guan developed an algorithm to detect atmospheric rivers in historical data, so they could connect the sky flow to extreme events on land. And they found that, if you look at just the top 2 percent most extreme wind- and rain- and snow-storms in the world's midlatitude regions—atmospheric rivers are linked to up to half of them.

Walise和他的同事管兵通过研发了一个算法来检测大气河流的历史数据，所以，他们可以将空气的流动和陆地上发生的一些极端的现象联系到一起。结果，发现，如果仅看世界中纬度地区2%极端天气，如暴风、骤雨或者暴风雪等——一半以上的上述现象与大气河流有关。

And of the 19 windstorms in Europe that cost insurance companies the most money—billions of dollars in damage—atmospheric rivers were behind three-quarters of those events. The study is in the journal Nature Geoscience.

欧洲发生的19起强暴风雪，刷高了保险公司的赔偿金额——数十亿美元的赔偿费——而有3/4的事件都与大气河流有关。该研究结果发表在《自然地球科学》杂志上。

Looking ahead, as global temperatures rise, that warmer air holds more water vapor. "And so the tendency looks like, if the climate does warm, you would tend to have stronger or more frequent atmospheric rivers." And as this study shows: it won't just be that a hard rain's gonna fall. We'll be blowing in the wind, too.

未来，随着全球气温的升高，温度升高，空气中水蒸气的含量也将增多。按照现在的发展趋势，如果气候变暖，那么未来，我们会遇到更强、频率更平凡的大气河流。正如研究结果中描述的那样：未来我们不止沐浴暴雨，还会随风飘荡。