時差N小時:聞起來像雨的味道

If you've been outside before a rainfall in the spring,you might have noticed a particularly fresh or sweetsmell that seeps into the air a few minutes beforethe first drops begin to fall. If you're familiar withthis smell, it's a great way to predict when the rainis about to start. What, exactly, makes the air smelllike rain?

如果在春雨降臨之前呆在外面，那么你可能會注意到：在第一滴雨落下之前的幾分鐘里，空氣中彌漫著一股特別的清香。如果你對這種味道很熟悉，那么你就能很好地預測什么時候開始下雨。到底是什么讓空氣充滿雨的味道呢?

A lot of stories and folk tales have arisen to explain this odor. Long ago, people used to believethat rain clouds picked up sweet smells from Heaven, and the rain carried these angelic odors toEarth. A more up-to-date–but equally incorrect–version of this folktale is that the smell comesfrom ozone, carried from the upper atmosphere by the falling rain.

許多故事和民間傳說紛紛出現(xiàn)，試圖解說這種氣味的由來。很久以前，人們以為是烏云吸收了天上的甜蜜氣味，然后由雨點將這種天使的氣味帶到人間。還有另一個最新但同樣錯誤的故事版本，說這種氣味來自于臭氧，下雨時將臭氧從高空帶到地面。

In fact, that fresh smell isn't coming down from the sky at all. It's coming up, from the groundbeneath your feet. As a spring rain approaches, the humidity level at the ground tends toincrease. Moist air is much better than dry air at transmitting smells–this is why you might usewarm, steaming water to carry the smell from dried potpourri into the air of your house.

實際上這種清新的味道根本不是來自于天上。它來自于你腳下的泥土。當春雨來臨之際，地面的濕度水平會上升。潮濕的空氣比干燥的空氣傳播氣味的效果更好，這就是為什么你會選擇用溫暖的水蒸氣將干燥的花香擴散至整個屋子。

As the humidity rises, the moist air carries the fresh smell of oils, secreted by grass and otherground plants, up to your nose. It also carries the odors of ground dwelling bacteria andfungi. These smells are always in the air immediately above the ground, as you can test foryourself by sticking your nose into your lawn and breathing deeply. When a rainstormapproaches and the humidity climbs, the odor rises up from its earthly embrace and yousay–it smells like rain!

隨著濕氣加重，潮濕的空氣將草或者其它植物分泌的芳香的精油輸送入你的鼻子。同時也帶給你寄居地表的細菌和真菌的味道。這些氣味就停留在地表上方的空氣，你可以親自測試一下：將鼻子緊貼草叢，深深地呼吸。當暴雨來臨時濕度增加，氣味就掙脫了塵世的擁抱，這時你可以說——這聞起來像雨。