(单词翻译:单击)
I bet that the last time you went to the beach, the wind was blowing in off the water.
我敢打赌,你最后一次去海滩的时候,海风正从水面吹来 。
Maybe it was just a pleasant breeze, maybe something a little stronger.
或许是令人愉快的微风,也或许是更强一点的风 。
But it was definitely coming in off the water.
但是它的确来自于水面 。
What's more, a breeze will be coming in off the water the next time you go to the beach.
更重要的是,你下次去海滩的时候微风又会徐徐吹来 。
How do I know? Easy.
我为什么会知道?那太容易了 。
Wind is caused by differences in the temperature of air.
风是由空气的温差引起的 。
If you have a lot of hot air in one location and a lot of cold air next to it, the line where they meet will be windy.
如果一个地方有大量的热空气,它的旁边又有大量的冷空气,那么冷热空气相交的地方就会形成风 。
That's because the hot air is rising and the cold air is rushing in to fill the space left behind. Whoosh!
因为热空气上升,冷空气就会迅速冲到热空气留下的位置里并填满整个空间 。
Now, here we are at the beach.
现在我们站在海滩上 。
What do you notice?
你注意到了什么?
Well, the sand under your feet retains heat pretty effectively. Once it is hot, it stays hot.
你脚下的沙子能够有效的保持热量 。一旦它变热了,它就会维持热度 。
Not so for ocean water, which is much harder to heat.
可是海水却很难变热 。
Think of how cold the water feels when you step into it off a hot beach.
想想当你从水中踏入炙热的沙滩时,会发现海水是多么的寒冷啊!
This distinction is true of land and sea in general.
总的来说,这就是陆地和海洋的真实区别 。
On a sunny day, the land stays hotter than the sea.
阳光明媚的日子,陆地比海洋要热很多 。
That means the air over the beach will be hotter than the air over the water.
那意味着海滩上空的空气将会比水面上空的空气热 。
And that means the air will be rising over the beach.
也就是说海滩上的热气将会上升 。
As the hot beach air rises up, the relatively cooler air over the water moves in to take its place.
随着海滩上空热空气的上升,水面上相对寒冷的空气就会流动过来代替热空气的位置 。
The result? A sunny day in summer creates its own breeze.
结果是什么呢?在夏天一个阳光灿烂的日子里有微风吹过 。