听写材料26.风

正确原文：

Weonly have a few minutes left, so I’d like to go over a couple of points beforewe move on. Remember that although there are both horizontal and verticalmovements of air, the term “wind” is applied only to horizontal movements, andthat more air is involved in those horizontal movements than in verticalmovements. And what causes these horizontal movements? Ultimately, it’s solarradiation. Because the unequal heating of the earth and the atmosphere produceshorizontal differences in air pressure, these differences set winds in motion.Essentially, winds are nature’s way of balancing out the uneven distribution ofair pressure over the earth. Secondly let me repeat my answer to the questionwe had before about wind direction. Many people get confused by what they hearin weather forecasts. We talk about the wind direction in terms of where thewind’s coming from, not where it’s blowing to. There’s a good reason for this.To weather forecasters, the origin of the wind is more important than itsdestination. The wind’s origin helps them predict the weather. Logically in thenorthern hemisphere, a north wind tends to bring colder weather, and a southwind warmer weather. I haven’t forgotten vertical movements of air, but wedon’t have time today to talk about them in depth. In our next class then, I’llbegin by discussing updrafts and downdrafts, and how they affect the weather. Isuspect most of you can guess which of the two brings to warm weather and whichbrings cold.

生词摘录：

1.    horizontal: adj. 水平的

2.    vertical: adj. 垂直的

3.    solar radiation: 太阳辐射

4.    essentially:adv. 本质上

5.    distribution:n. 分配，分布

6.    destination:n. 目的地，终点

7.    updrafts: n. 上升气流，向上排气

8.    downdrafts: n. 下降气流，回流，倒风