Summer Breeze, Makes Me Feel Fine
風(fēng)是大家最熟悉的自然現(xiàn)象,要了解風(fēng)的形成必須了解包圍著地球的大氣的運(yùn)動。大氣的流動也像水流一樣是從壓力高處往壓力低處流。太陽能正是形成大氣壓差的原因。地球上各處的地形地貌也會影響風(fēng)的形成,如海邊,由于海水熱容量大,接受太陽輻射能后,表面升溫慢,陸地?zé)崛萘啃?,升溫比較快。于是在白天,由于陸地空氣溫度高,空氣上升而形成海面吹向陸地的海陸風(fēng)。反之在夜晚,海水降溫慢,海面空氣溫度高,空氣上升而形成由陸地吹向海面的陸海風(fēng)。
Why is it always (1)breezy at the beach? Find out on this Moment of Science.
I bet that the last time you went to the beach, the wind was blowing in off the water. Maybe it was just a pleasant breeze, maybe something a little stronger. But it was definitely coming in off the water. What’s more, a breeze will be coming in off the water the next time you go to the beach.
How do I know? Easy.
Wind is caused by differences in the temperature of air. 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 (2)windy. That’s because the hot air is rising and the cold air is rushing in to fill the space left behind. Whoosh!
Now, here we are at the beach. What do you notice? Well, the sand under your feet retains heat pretty (3)effectively. Once it is hot, it stays hot. Not so for ocean water, which is much harder to heat. Think of how cold the water feels when you step into it off a hot beach.
This distinction is true of land and sea in general. On a sunny day, the land stays hotter than the sea. That means the air over the beach will be hotter than the air over the water. And that means the air will be rising over the beach.
As the hot beach air rises up, the relatively cooler air over the water moves in to take its place. The result? A sunny day in summer creates its own breeze.
譯文:
夏天的風(fēng),令人舒暢
我敢打賭,你最后一次去海灘的時候,海風(fēng)正從水面吹來?;蛟S是令人愉快的微風(fēng),也或許是更強(qiáng)一點的風(fēng)。但是它的確來自于水面,更重要的是,你下次去海灘的時候微風(fēng)又會徐徐吹來。
我為什么會知道?那太容易了。
風(fēng)是由空氣的溫差引起的。如果一個地方有大量的熱空氣,它的旁邊又有大量的冷空氣,那么冷熱空氣相交的地方就會形成風(fēng)。因為熱空氣上升,冷空氣就會迅速沖到熱空氣留下的位置里并填滿整個空間。
現(xiàn)在我們站在海灘上。你注意到了什么?你腳下的沙子能夠有效的保持熱量。一旦它變熱了,它就會維持熱度??墒呛K畢s很難變熱。想想當(dāng)你從水中踏入炙熱的沙灘時,會發(fā)現(xiàn)海水是多么的寒冷啊!
總的來說,這就是陸地和海洋的真實區(qū)別。陽光明媚的日子,陸地比海洋要熱很多,那意味著海灘上空的空氣將會比水面上空的空氣熱,也就是說海灘上的熱氣將會上升。
隨著海灘上空熱空氣的上升,水面上相對寒冷的空氣就會流動過來代替熱空氣的位置。結(jié)果是什么呢?在夏天一個陽光燦爛的日子里有微風(fēng)吹過。
Notes:
(1)breezy['bri:zi] adj.有微風(fēng)的;輕松愉快的;通風(fēng)好的;活潑的
It was a lazy, breezy summer afternoon.
這是一個懶散的,起風(fēng)的夏日下午。
(2)windy['windi]adj. 多風(fēng)的,有風(fēng)的;腹脹的;吹牛的
And I like windy weather, too.
我也喜歡有風(fēng)的天氣。
(3) [i'fektivli] adv.有效地,生效地;有力地;實際上
Allocate the time effectively.
有效地分配時間。