60秒科学:Rain Zone Moving North

Rain Zone Moving North
An article in Nature Geoscience predicts that the rainiest area on Earth, the intertropical convergence zone, is moving steadily¹ north. Christie Nicholson reports

[The following is an exact transcript² of this podcast.]

If you’ve spoken to anyone in New York City—where Scientific American’s offices are—then you’ve heard about the rain, every day since mid-June.

Still, we’re not in the intertropical convergence zone, an area just north of the equator stretching across the Pacific that builds rain clouds 30,000 feet thick releasing as much as 13 feet of rain annually³.

But the rainiest place on Earth might reach us, eventually. Researchers report in the journal Nature Geoscience the zone is moving north at a rate of nearly a mile per year.

It’s important because it supplies freshwater to a billion people in the tropics.
Researchers studied Washington Island in the Pacific that gets 10 feet of rain annually. Core samples revealed that it was desert-like only 400 years ago. A similar situation was found in Palau, now in the heart of the convergence zone. Also, the now arid⁴ Galapagos Islands had a very wet climate about 400 years ago.

Researchers predict that this zone will be more than 75 miles north of its current position as early as midcentury, having profound economic and cultural implications for those who currently depend upon it.

—Christie Nicholson

1 steadily   

adv.稳定地；不变地；持续地

参考例句：

• The scope of man's use of natural resources will steadily grow.人类利用自然资源的广度将日益扩大。
• Our educational reform was steadily led onto the correct path.我们的教学改革慢慢上轨道了。

2 transcript   

n.抄本，誊本，副本，肄业证书

参考例句：

• A transcript of the tapes was presented as evidence in court.一份录音带的文字本作为证据被呈交法庭。
• They wouldn't let me have a transcript of the interview.他们拒绝给我一份采访的文字整理稿。

3 annually   

adv.一年一次，每年

参考例句：

• Many migratory birds visit this lake annually.许多候鸟每年到这个湖上作短期逗留。
• They celebrate their wedding anniversary annually.他们每年庆祝一番结婚纪念日。

4 arid   

adj.干旱的；(土地)贫瘠的

参考例句：

• These trees will shield off arid winds and protect the fields.这些树能挡住旱风,保护农田。
• There are serious problems of land degradation in some arid zones.在一些干旱地带存在严重的土地退化问题。