If you break it, EN stands for El Nino, and SO stands for Southern Oscillation.

如果把它拆開，EN 代表厄爾尼諾，SO 代表南方濤動。

Because ENSO phenomena mostly occurs at the Southern Hemisphere, just right below the equator.

因為厄爾尼諾/南方濤動現象大多發生在南半球，也就是赤道的正下方。

And when you look at the term oscillation, it gives us a hint that something oscillates from one place to another, or back and forth.

當你看到 "振盪 "這個詞時，它給了我們一個暗示，即某物會從一個地方振盪到另一個地方，或者來回振盪。

If you want, you can pause the video and think about what could be that thing.

如果你願意，可以暫停視頻，想想那會是什麼東西。

Well, it's the temperature that we are talking about.

我們說的是溫度。

And not just any temperature, ocean temperature.

而且不是普通的溫度，是海洋溫度。

It is the ocean temperature that oscillates back and forth from warm temperature to cold temperature, and vice versa.

海洋溫度從暖溫區到低溫區來回擺動，反之亦然。

Now, the next question that should be in your mind is, which ocean are we talking about?

現在，你應該想到的下一個問題是，我們說的是哪個海洋？

I'll give you a hint, it's the largest one, Pacific Ocean.

我給你個提示，那是最大的一個，太平洋。

You see, Pacific Ocean is this large pool of water that exists on the western side of the American continent, and eastern side of the Asian and Australian continent.

你看，太平洋是存在於美洲大陸西側、亞洲和澳洲大陸東側的一個大水潭。

This large pool of water gets intensely warm due to the fact that it exists right at the equator.

由於位於赤道上，這一大片水域的溫度非常高。

And we all know that the equatorial region receive great amount of sun rays all throughout the year.

我們都知道，赤道地區全年都能接收到大量的太陽光。

So far, we have learned what and where ENSO takes place.

到目前為止，我們已經知道厄爾尼諾/南方濤動發生的原因和地點。

Now it's time to know how it all happens.

現在是時候瞭解這一切是如何發生的了。

To understand how ENSO occurs, we will need to break it into three phases.

要了解厄爾尼諾/南方濤動是如何發生的，我們需要將其分為三個階段。

That's how it will make sense, and step by step, the concept will get clearer.

這樣才有意義，一步一步地，概念就會越來越清晰。

The first phase is neutral phase.

第一階段為中性階段。

Actually, there is no such thing as a neutral phase when it comes to any of nature's phenomena.

事實上，自然界的任何現象都不存在中性階段。

You see, nature has a constant ongoing cycle that has never stopped.

你看，大自然不斷循環往復，從未停止過。

But for our own understanding, we will have to create a neutral state where we can see how a particular thing starts and goes on.

但是，為了我們自己的理解，我們必須創造一種中立的狀態，在這種狀態下，我們可以看到某一特定事物是如何開始和發展的。

So the first phase among the three phases is the neutral phase.

是以，三相中的第一相就是中性相。

In this phase, the central Pacific Ocean is warm.

在這一階段，太平洋中部溫暖。

Now let's bring in the trade winds.

現在讓我們吹起信風。

Trade winds are these wind that blows in the tropical region from eastern side to the western side.

信風是熱帶地區從東邊吹向西邊的風。

They are also known as tropical easterlies.

它們也被稱為熱帶東風。

So as we know that the equator receives great amount of sun rays, and that's what warms the Pacific Ocean, the trade winds pushes the warm ocean current towards the Asian side, because trade winds blow from east to west, and that makes the Western Pacific Ocean warm.

是以，我們知道赤道接受大量的太陽光，這就是太平洋變暖的原因，信風將暖洋流推向亞洲一側，因為信風是從東往西吹的，這使得西太平洋變暖。

You know the region around New Zealand, Australia, and Indonesia.

你知道紐西蘭、澳洲和印度尼西亞周邊地區。

This region is called the Western Pacific Pool.

這個區域被稱為西太平洋水池。

Here the ocean temperature is warm.

這裡的海洋溫度較高。

The warm ocean current affects the surrounding atmosphere by increasing the temperature as well as the moisture content.

暖洋流通過提高溫度和含水量來影響周圍的大氣。

And we know that warm air rises high into the atmosphere.

我們知道，暖空氣會上升到大氣層的高處。

It is through the convection process, and that's how clouds are formed, and then it rains.

它是通過對流過程形成的，雲就是這樣形成的，然後就下雨了。

The warm air then travels east towards Eastern Pacific Ocean.

暖空氣隨後向東進入東太平洋。

You know the region near South America, especially countries like Ecuador and Peru.

大家都知道南美洲附近的地區，尤其是厄瓜多爾和祕魯等國。

The warmer air, when it goes up, it reaches the end of troposphere.

暖空氣上升後，會到達對流層的末端。

And if you know, the top of the troposphere is cold.

對流層的頂部是寒冷的。

When warm air meets cool air, slowly it loses its moisture content, and the air becomes dry.

當暖空氣遇到冷空氣時，其含水量會慢慢流失，空氣就會變得乾燥。

The dry air travels towards the Eastern Pacific side and comes down over the Peruvian coastal region, making the region cold.

乾燥空氣流向東太平洋一側，在祕魯沿海地區上空降落，使該地區變得寒冷。

This pattern of rising air in the west and falling in the east continues, and it is known as Walker Circulation.

這種西部空氣上升、東部空氣下降的模式一直持續，被稱為 "沃克環流"。

So this was the neutral phase.

是以，這是中性階段。

I hope you understood this cycle.

我希望你能理解這個循環。

It's plain and simple.

簡單明瞭。

Now comes the second phase.

現在是第二階段。

It's called El Niño.

這就是厄爾尼諾現象。

So in the neutral phase, we saw that the trade winds played an important role in pushing the warm ocean current towards the Western Pacific.

是以，在中性階段，我們看到信風在將暖洋流推向西太平洋方面發揮了重要作用。

Now in this phase, the trade winds are weak.

在這一階段，信風較弱。

Yes, there are a few months in a year when the trade winds are weak.

是的，一年中會有幾個月信風較弱。

When the trade winds are weak, the warm ocean current do not get any kind of push.

信風弱時，暖洋流得不到任何推動。

So what happens is, the warm pool of ocean water at the Western Pacific slowly moves towards the central and eastern side of the Pacific Ocean.

是以，西太平洋的暖海水池會慢慢向太平洋中部和東部移動。

So this is where the oscillation term comes in.

這就是振盪項的由來。

You see the warm ocean current is replacing the cold ocean current that exists in the central and eastern Pacific.

你看，暖洋流正在取代太平洋中部和東部的冷洋流。

When I say replace, what I mean is that the cold water is dense and it settles down in deep ocean.

我說的 "取代 "是指冷水密度大，在深海中沉澱下來。

And warm water goes up and takes over the surface of the ocean.

暖水上升，佔據了海洋表面。

Okay, I hope you're understanding.

好吧，希望你能理解。

When this warm ocean current moves, everything that is associated with it, like the convection process, then the formation of rain cloud, everything moves along with this warm ocean current.

當這股暖洋流移動時，與之相關的一切，比如對流過程，然後雨雲的形成，都會隨著這股暖洋流移動。

What you will notice now is that the walker circulation that we saw in the neutral phase, that one big looping pattern, it's now breaking into two parts.

你現在會發現，我們在中性階段看到的漫步者環流，即一個大的循環模式，現在抽成了兩部分。

Just look at this loop.

看看這個循環就知道了。

As a result, the ocean temperature near Australia is cool and there is no rain.

是以，澳洲附近的海洋溫度較低，沒有降雨。

Though the inland parts of Australia witness a severe drought condition.

儘管澳洲內陸地區出現了嚴重乾旱。

But on the other hand, near the Peruvian coast, the warm pool of ocean current brings heavy rain, flood to the American continent.

但另一方面，在祕魯海岸附近，溫暖的洋流給美洲大陸帶來了暴雨和洪水。

So whenever you hear the word El Niño, immediately think of warm ocean current.

是以，每當你聽到厄爾尼諾這個詞，就會立刻想到溫暖的洋流。

And the third phase is La Niña.

第三階段是拉尼娜現象。

This is similar to the neutral phase.

這與中性階段類似。

In this phase, the trade winds are strong.

在這一階段，信風強勁。

Since trade winds blow from east to west, hence it pushes the warm ocean current from the Eastern Pacific towards the Western Pacific.

由於信風由東向西吹，是以它將東太平洋的暖洋流推向西太平洋。

Now imagine this, cold water is dense and it settles down in deep ocean.

現在想象一下，冷水密度大，會沉澱在深海中。

So that means the temperature of the ocean surface is warm.

是以，這意味著海洋表面的溫度很高。

Now, if the trade wind pushes the warm surface ocean current towards the Western Pacific, the cold water from the deep ocean immediately comes up at the surface.

現在，如果信風將溫暖的表層洋流推向西太平洋，深海的冷水就會立即浮出海面。

There's a word given to it.

有一個詞來形容它。

It's called thermocline.

這就是所謂的溫躍層。

Thermocline is the rising part of water temperature.

溫躍層是水溫上升的部分。

And the rest of the process is same.

其餘的過程也是一樣。

We saw that in the neutral phase.

我們在中性階段就看到了這一點。

Western Pacific region of Australia, Indonesia, New Zealand gets heavy rain, storm.

澳洲、印度尼西亞和紐西蘭的西太平洋地區遭遇暴雨和風暴。

The effect of La Niña is more on these countries than El Niño.

與厄爾尼諾現象相比，拉尼娜現象對這些國家的影響更大。

So El Niño is a warm ocean current and La Niña is a cold ocean current.

是以，厄爾尼諾是暖洋流，拉尼娜是冷洋流。

Remember that.

記住這一點。

If El Niño is at the Eastern Pacific, then La Niña will be at the opposite region that is Western Pacific.

如果厄爾尼諾現象出現在東太平洋，那麼拉尼娜現象就會出現在相反的區域，即西太平洋。

And it oscillates back and forth.

它來回擺動。