1
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为什么赤道远比你想象中更会“搅动”全球空气？九十秒，看懂三圈环流！
Why does the equator stir air around the globe? Learn the three-cell model in ninety seconds!

2
00:00:06,150 --> 00:00:14,850
太阳把赤道附近加热得更强，热空气上升；高纬较冷，空气更容易下沉。这就是理想环流的能量起点。
Stronger solar heating near the equator lifts warm air; colder high-latitude air sinks more readily.

3
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看北半球第一条闭合路线：赤道上升，高空向约三十度，随后下沉，再沿地表回到赤道。每个半球都有这样一圈。
In the Northern Hemisphere: air rises at 0°, moves aloft to about 30°, sinks, then returns at the surface.

4
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第二圈在约三十到六十度之间：三十度附近下沉，地表向六十度，六十度附近上升，高空返回。它受两侧环流和斜压过程影响，不是简单的独立热对流。
Between about 30° and 60°: air sinks near 30°, flows poleward, rises near 60°, and returns aloft. It is not a simple independent thermal cell.

5
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第三圈：冷空气在极地下沉，地表由九十度流向约六十度，随后上升，高空再返回极地。费雷尔与极地环流在约六十度汇合上升。
Cold air sinks at the pole, flows to about 60°, rises, then returns aloft. The Ferrel and Polar cells meet and rise near 60°.

6
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地表的回到赤道气流，偏成东北信风；三十到六十度吹西风带；极地来的叫极地东风。风按来向命名，西风就是从西边吹来。
Surface flow becomes the NE trades, westerlies, and polar easterlies. Winds are named for where they come from.

7
00:00:58,150 --> 00:01:08,850
为什么偏？地球自转带来科里奥利效应。北半球相对运动方向偏右，南半球偏左。注意：不是永远向东；向北会偏东，向南会偏西。
Earth rotation causes the Coriolis effect: right of motion in the north, left in the south, not always east!

8
00:01:09,150 --> 00:01:16,850
这有什么用？约三十度附近空气下沉，升温加压，云雨较难发展，所以许多副热带地区偏干燥。
Near 30°, sinking air warms and clouds struggle to grow, helping explain dry subtropical regions.

9
00:01:17,150 --> 00:01:24,850
别忘了：这是多年平均的理想示意，南北半球各有三圈；海陆和季节会让真实气流更复杂，纬度边界也会移动。
This is an idealized long-term average: three cells per hemisphere. Real flow and latitude boundaries shift.

10
00:01:25,150 --> 00:01:29,850
不均匀加热，三圈闭合，风向相对运动偏转。现在，你能沿着每一圈讲一遍吗？
Uneven heating, three closed cells, and deflection relative to motion. Can you trace each loop?