What is El Niño (ENSO)?

Summary

El Nino, part of the ENSO (El Nino Southern Oscillation), is a weather pattern affecting the equatorial Pacific, causing fluctuations between high and low pressure areas. Normally, trade winds push warm water west, creating a wet Indonesia and dry South American coast. El Nino disrupts this, weakening winds and causing warm water to accumulate off South America, leading to increased rainfall and potential mudslides. It also impacts global climate, causing droughts and floods in various regions, affecting agriculture, fisheries, and even politics. The opposite effect, La Nina, brings drier conditions to the eastern Pacific and wetter to the west.

Takeaways

• 🌊 El Nino is a fluctuating weather pattern in the Pacific Ocean around the equator, part of the ENSO (El Nino Southern Oscillation) system.
• 🔄 Southern Oscillation refers to weather changes in the Southern Hemisphere, which is interconnected with El Nino.
• 🌀 Normal weather patterns involve high pressure in the southeast Pacific, with trade winds moving warm water westward and cold water upwelling off South America.
• 🏜 The west coast of South America is typically dry due to cold upwelling waters, while Indonesia's east is wet due to warm waters.
• 🌡 Wind, air pressure, and sea temperature are interdependent, reinforcing the normal weather pattern.
• 🌀 A decrease in wind strength can initiate El Nino, reducing the temperature difference between the eastern and western Pacific.
• 🔥 El Nino occurs every 2 to 7 years, with weakened trade winds causing warmer waters to linger off South America, leading to increased rainfall in typically dry areas.
• 🐟 Warmer waters during El Nino have less fish, affecting local fisheries, and are first noticed around Christmas, hence the name 'El Nino'.
• 🌧 Conversely, Indonesia experiences colder waters, higher air pressure, and drier conditions during El Nino.
• 🌍 El Nino has global impacts, influencing rainfall and temperature patterns in various regions, causing floods in some areas and droughts in others.
• 🌀 La Nina is the opposite effect of El Nino, with cooler than average waters in the eastern Pacific, leading to drier conditions there and wetter conditions in the west.

Q & A

What is El Nino and what does its full name represent?

El Nino is a fluctuating weather pattern around the equator in the Pacific, and its full name is ENSO, which stands for El Nino Southern Oscillation, referring to weather fluctuations in the Southern Hemisphere.

What is the normal weather pattern in the Pacific Ocean?

In a normal situation, there is a high-pressure area in the southeastern part of the Pacific Ocean. Trade winds blow east to west, taking cold seawater to the west where it heats up and creates a low-pressure area, causing air to rise and rain, especially over Indonesia.

How does the normal weather pattern affect the climate on the west coast of South America and eastern Indonesia?

The normal weather pattern results in the west coast of South America being dry due to cold seawater and promoting upwelling, while eastern Indonesia is very wet due to warm seawater.

What causes El Nino to occur?

El Nino occurs when the strength of the trade winds decreases, leading to less warm seawater being blown westward, which in turn causes less cold water to rise in the eastern Pacific, reducing the temperature difference and weakening the winds further.

How often does El Nino typically occur?

El Nino occurs approximately every 2 to 7 years.

What are the effects of El Nino on the temperature of the ocean water near South America?

During El Nino, the ocean water just west of South America warms up, sometimes by as much as 6 degrees Celsius more than the normal temperature, creating a low-pressure area and increased precipitation.

Why is El Nino associated with the name 'Christ child'?

El Nino is named after the Christ child, or 'El Nino' in Spanish, because South American fishermen noticed that the phenomenon often occurred around Christmas.

What is the opposite effect of El Nino called, and what does it represent?

The opposite effect of El Nino is called La Nina, which is Spanish for 'girl' and represents a situation where the seawater cools above average in the eastern Pacific, causing stronger winds to the west and a higher than normal temperature difference between the eastern and western Pacific.

How does El Nino impact global weather patterns?

El Nino affects global weather patterns by increasing rainfall and flooding in some areas like Peru, Ecuador, and parts of the United States, while causing droughts in others such as Indonesia, India, Southern Africa, and Australia.

What are the potential consequences of El Nino on agriculture and fisheries?

El Nino can greatly affect agriculture and fisheries by causing droughts or floods, leading to crop failures, reduced fish populations, increased food prices, and potentially famine and political consequences.

How does El Nino influence hurricane activity in the Atlantic and Pacific Oceans?

During an El Nino, there are fewer hurricanes in the Atlantic area but an increase in the number of hurricanes in the Pacific Ocean due to the increased heat and moisture in the atmosphere.

Outlines

00:00

🌊 El Nino: The Weather Phenomenon Explained

This paragraph introduces El Nino, a weather pattern that fluctuates around the equator in the Pacific Ocean, as part of the ENSO (El Nino Southern Oscillation) system. It explains the normal weather pattern, which includes high pressure in the southeastern Pacific, trade winds moving warm water westward, and the resulting low pressure area near Indonesia that leads to rain. The west coast of South America experiences upwelling of cold water, creating a high-pressure area and desert conditions. The paragraph also describes how changes in wind strength can lead to El Nino, characterized by warmer waters off the coast of South America, causing precipitation in typically dry areas and affecting marine life. The name 'El Nino' is derived from its frequent occurrence around Christmas, and its counterpart, 'La Nina,' is also mentioned, which leads to the opposite effects. The paragraph concludes by discussing the global impact of El Nino on weather patterns, including increased rainfall in some areas and droughts in others, affecting agriculture, fisheries, and even political stability.

05:04

🌐 Global Impact of El Nino

The second paragraph succinctly encapsulates the broader implications of El Nino, emphasizing its role as a significant change in the weather pattern around the equator in the Pacific Ocean. It highlights the far-reaching effects of El Nino on a global scale, affecting not only the Pacific region but also weather conditions worldwide. The summary underscores the interconnectedness of weather systems and the profound influence that El Nino has on various aspects of life on Earth, from precipitation patterns to agricultural yields and even geopolitical dynamics.

Keywords

💡El Nino

El Nino refers to a climate pattern characterized by unusually warm ocean temperatures in the Equatorial Pacific, which affects weather worldwide. In the video, it is described as part of the ENSO (El Nino Southern Oscillation) system and is central to the video's theme of understanding weather fluctuations around the equator in the Pacific.

💡ENSO

ENSO stands for El Nino Southern Oscillation, which encompasses both El Nino and its opposite, La Nina. It is a key concept in the video as it represents the oscillation between warmer and cooler than average sea surface temperatures in the Pacific Ocean, influencing global weather patterns.

💡Southern Oscillation

Southern Oscillation is the atmospheric component of ENSO, involving fluctuations in atmospheric pressure between the eastern and western Pacific. The video explains how it is linked to El Nino, with changes in wind patterns and air pressure playing a crucial role in the development of El Nino conditions.

💡Trade Winds

Trade Winds are the dominant easterly winds in the tropics, which in the context of the video, are responsible for pushing warm surface waters westward in the Pacific. A decrease in their strength is a precursor to El Nino, as it results in less warm water being moved westward, altering the usual weather patterns.

💡Upwelling

Upwelling is an oceanographic phenomenon where deep, cold water rises to replace surface water that has been moved away by wind. In the video, it is mentioned that upwelling occurs on the west coast of South America, contributing to the creation of cold, dry conditions under normal weather patterns.

💡High Pressure Area

A high-pressure area is a region where the atmospheric pressure is higher than the surrounding areas. In the video, it is associated with areas of descending air and clear skies, such as the west coast of South America during normal conditions, where cold seawater leads to high atmospheric pressure and dryness.

💡Low Pressure Area

A low-pressure area is characterized by lower atmospheric pressure compared to the surrounding regions, often associated with rising air and precipitation. The video describes how warm seawater in the western Pacific creates a low-pressure area, leading to increased rainfall, especially in Indonesia.

💡Precipitation

Precipitation refers to any form of water that falls from the atmosphere, such as rain or snow. The video discusses how El Nino affects precipitation patterns, causing increased rainfall in some areas like South America and decreased rainfall in others, such as Indonesia.

💡La Nina

La Nina is the opposite phase of El Nino, characterized by cooler than average sea surface temperatures in the central and eastern Pacific. The video explains that La Nina can lead to a drier eastern Pacific and a wetter western Pacific, with global weather impacts opposite to those of El Nino.

💡Drought

Drought is a period of unusually low precipitation, leading to water scarcity. The video mentions that El Nino can cause droughts in areas like Indonesia, India, and Australia, affecting agriculture and potentially leading to food shortages and political instability.

💡Hurricanes

Hurricanes are intense tropical storms with high winds and heavy rainfall. The video explains that El Nino can influence the number of hurricanes in different ocean basins, reducing them in the Atlantic while potentially increasing them in the Pacific due to increased heat and moisture in the atmosphere.

Highlights

El Nino is a fluctuating weather pattern in the Pacific around the equator, known as ENSO (El Nino Southern Oscillation).

Southern Oscillation refers to weather fluctuations in the Southern Hemisphere, influencing El Nino.

Normal weather patterns involve high pressure in the southeast Pacific and trade winds influencing seawater temperature and movement.

Warm seawater in Indonesia creates a low-pressure area, causing air to rise and rain, while cold seawater in South America leads to high pressure and dry conditions.

El Nino disrupts the normal weather pattern by reducing wind strength, leading to less cold water upwelling in the eastern Pacific.

Decreased temperature difference between the western and eastern Pacific due to El Nino results in weaker winds and altered air pressure.

El Nino occurs approximately every 2 to 7 years, with varying impacts on global weather patterns.

During El Nino, the weakening of trade winds causes ocean water to warm off South America, leading to increased precipitation in normally dry areas.

El Nino's impact on South America includes potential mudslides due to heavy rainfall in areas with little vegetation.

The term 'El Nino' originates from the observation of warmer waters around Christmas, likened to the Christ child.

Contrastingly, Indonesia experiences colder than normal seawater and increased air pressure during El Nino, leading to drier conditions.

Prolonged El Nino conditions can cause a shift in ocean currents, allowing cooler deep seawater to resurface and restore normal weather patterns.

La Nina is the opposite effect of El Nino, characterized by above-average cooling in the eastern Pacific, leading to drier conditions there and wetter conditions in the west.

El Nino has global effects, influencing rainfall and weather patterns in regions such as Peru, Ecuador, California, and causing droughts in Indonesia, India, Southern Africa, and Australia.

The occurrence of El Nino can lead to a decrease in Atlantic hurricanes and an increase in Pacific hurricanes due to atmospheric heat and moisture.

El Nino's impact extends beyond weather, potentially causing food price increases, famine, political instability, and environmental changes like forest fires.

The interplay between wind, air pressure, and seawater temperature during El Nino demonstrates the interconnectedness of global weather systems.

Transcripts

In this video El Nino will be explained; a fluctuating weather pattern in the area around the equator in the Pacific.

The full name of El Nino is ENSO: El Nino Southern Oscillation.

Southern Oscillation means that there is a weather fluctuation in the Southern Hemisphere which is called El Nino.

So to understand El Nino, we must first explain the normal weather pattern.

In a normal situation there is a high pressure area in the southeastern part of the Pacific Ocean.

Here the wind turns counterclockwise and this wind takes cold seawater from the south to the equator.

The trade winds from the east take this seawater to the west.

This seawater heats up and is warm by the time it arrives at Indonesia. This creates a low pressure area, causing air to rise and rain.

On the west coast of South America, the seawater on the surface therefore moves to the west, promoting upwelling of cold water.

This cold seawater creates cold, descending air, so a high-pressure area.

Moreover, this water does not evaporate quickly, creating deserts in the west coast of South America.

In short; in the normal weather pattern, the west coast of South America is dry, due to the cold sea water, and the eastern area of Indonesia is very wet, due to the warm sea water.

Wind, air pressure and the temperature of the sea water reinforce each other.

Suppose the wind decreases in strength. As a result, less warm seawater is blown towards the west.

As a result, less cold ocean water rises in the eastern Pacific Ocean, making it less cold.

As a result, the difference in temperature between the western part and the eastern part of the ocean decreases.

As already explained, warm seawater creates a low pressure area and cold seawater creates a high pressure area.

Because the difference in temperature of the seawater decreases, the difference in air pressure also decreases, so that the wind also becomes less strong.

Because the winds decrease, less water is moved westward again and the temperature difference between the eastern and western part of the Pacific decreases even more.

In this way the wind, sea temperature and air pressure influence each other.

Although it is not known where it exactly starts, it is clear that if either the wind, or the temperature of the seawater, or the air pressure change, the other two are also affected and the weather pattern changes.

El Nino occurs about every 2 to 7 years.

The strength of the trade winds decreases, making the wind to the west less strong.

As a result, the ocean water remains just west of South America and warms up there, up to a maximum of 6 degrees Celsius more than the normal temperature!

This creates a low pressure area and precipitation falls in a normally dry area.

Because there is hardly any vegetation in this area, because normally there is no precipitation, the rainwater is not retained and mudslides can occur.

The warm ocean water contains much less fish. South American fishermen noticed that this frequently occurs around Christmas.

They therefore called it El Nino, which is Spanish for "boy child", referring to the Christ child.

In the area around Indonesia, the seawater is colder than normal.

As a result, the air pressure increases and less water evaporates.

This makes it a lot drier than normal. Agriculture and fisheries are thus greatly affected in both areas.

If this situation continues for a long time, the warm seawater in the eastern Pacific Ocean will eventually flow north and south.

Deeper seawater, which is cooler, can now resurface.

As a result, the surface temperature in the eastern Pacific Ocean is getting colder and the weather is returning to the normal pattern.

Sometimes, however, the seawater cools above average in this area.

This creates an extremely high pressure area, causing winds to the west to become stronger, more seawater to flow west,

more deep, cold seawater to flow to the surface, creating a higher than normal temperature difference between the eastern and western Pacific.

This will make it drier than normal in the eastern Pacific and even wetter than normal in the western Pacific.

This opposite effect is called La Nina. This is Spanish for "girl" and thus the counterpart of El Nino, the boy.

El Nino affects not only the Pacific around the equator, but many more areas!

The warm sea in the eastern Pacific Ocean creates heat and water vapor in the atmosphere, which can increase rainfall and flooding in many places in the world, such as in Peru and Ecuador.

Also in the southern part of the United States, such as in California, it usually rains more after an El Nino.

At the same time, it is much drier in other places in the world, such as Indonesia, India, Southern Africa and Australia.

The drought can cause forest fires or crop failures. This can cause food prices to rise and famine, which in turn can have political consequences.

Furthermore, fewer hurricanes arise in the Atlantic area during an El Nino, but the number of hurricanes in the Pacific Ocean increases, because there is more heat and moisture in the atmosphere.

In short; El Nino is a change in the normal weather pattern around the equator in the Pacific Ocean and has global effects.