时差N小时 为什么夜晚比白天平静(上)

More often than not, the wind dies down at night after a blustery day.

通常情况下，大风刮了一整天后在夜晚会逐渐平息下来。

Where does the wind go? Why are nights generally more calm than days?

大风去了哪里呢？为什么夜晚一般比白天平静呢？

The difference between calm nights and windy days is the sun.

平静的夜晚与多风的白天之间的差异源于太阳。

During the day, the sun warms the surface of the Earth, which in turn warms the atmosphere above it.

白天，太阳照射导致地表温度升高，进而使大气温度随之上升。

But at sunset, the earth’s surface and the layers of the atmosphere directly above it cool faster than higher layers of the atmosphere.

日落时，地表温度与大气温度比高层大气下降得更快。

That creates a stable temperature pattern, with dense¹, cool air on the ground and less dense, warmer air above.

因此形成一种稳定的气温模式，地面空气的密度大，温度较低；而地面上方的空气较稀薄，温度较高。

And that’s a little crazy, because normally² the atmosphere gets cooler as you go up!

听起来有些不可思议，因为通常情况下，气温是随着高度的增加而递减的。

1 dense   

a.密集的，稠密的，浓密的；密度大的

参考例句：

• The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。
• The path was completely covered by the dense foliage. 小路被树叶厚厚地盖了一层。

2 normally   

adv.正常地，通常地

参考例句：

• I normally do all my shopping on Saturdays.我通常在星期六买东西。
• My pulse beats normally.我脉搏正常。