Top 10 Facts about the Weather Phenomenon El Nino

Top 10 Facts about the Weather Phenomenon El Nino
Top 10 Facts about the Weather Phenomenon El Nino

[schema type=”event” evtype=”Event” name=”El Nino” description=”El Nino is a weather phenomenon characterized by heavier than usual winter precipitation. El Nino is caused by a warm ocean current of varying intensity that usually occurs after late December. El Nino starts in the Pacific ocean along the coast of Ecuador and Peru. El Nino can cause catastrophic weather conditions worldwide.” ]


Top 10 Facts about the Weather Phenomenon El Nino

Every few years, rumors about an often talked about, but little understood, weather pattern called El Nino begin to take over the news. As soon as signs of the season begin to show, scientists and forecasters begin desperately trying to predict what the next few months will bring.

El Nino was first noticed by Peruvian fisherman who discovered that every three to seven years, it became harder to fish in their usual fishing spots. The period almost always showed up around Christmas time. The Peruvians gave it an ironic name, due to its schedule, and began to call it El Nino, which means ‘the baby boy’ in Spanish.

As El Nino becomes more frequent and more powerful, the implications of this natural front become more serious. But, why are the worlds’ news sources so upset about the possibility of a desperately needed wet winter in California? Is that not a good thing for a state that seems to be in a perpetual drought?

What many people don’t understand is that El Nino is not just a front that brings heavy rains to the western part of the United States. El Nino is a naturally occurring weather pattern that causes disruptions all over the world. From Sydney to Los Angeles and even as far as London, it is not just the areas on the Pacific Rim that see both the positive and devastating effects of El Nino.

El Nino is inevitable, but it can be predicted. In order to best protect yourself, your home and your neighborhood from the damaging effects of this weather, it is best to understand it. Here are the 10 easy steps you need to understand the weather phenomenon called El Nino:

  1. El Nino is Dependent on the Conditions in the Pacific Ocean

The Pacific Ocean is where El Nino is born
The Pacific Ocean is where El Nino is born

The ocean has one of the biggest influences on the weather. It covers almost 70 percent of the planet, and the Pacific Ocean is the largest body of water on earth. The Pacific Ocean alone wraps around half of the Earth and covers the equator. The ocean forms the coastlines of south-east Asia and Australia and continues all the way to the western coastlines of North and South America. It also stretches from the Bering Strait in the Arctic almost all the way to Antarctica.

Ocean temperatures change naturally, but significant changes in ocean temperatures will have bigger effects on the weather. When the Pacific grows warmer, the heat is absorbed by the atmosphere, and then is redistributed in other oceans. The ocean temperatures that affect El Nino are located near the equator in the Pacific Ocean. This is where the water is the warmest because it gets the most sunlight due to the Earth’s axis.

In a normal year, the warm water in the equatorial regions of the Pacific Ocean will be blown towards Indonesia by the winds that blow from east to west. Winds that blow from east to west are called prevailing, or trade, winds and these the predominant kinds of wind gusts that the earth experiences. The direction of the gusts is primarily controlled by the way the Earth spins- which does not frequently change.

  1. Warm Waters Cause More Rainfall

El Nino is caused by warm ocean water
El Nino is caused by warm ocean water

The temperature of the ocean water is cyclical because the temperatures are affected by atmospheric conditions which are, in turn, affected by the oceans temperatures. When the atmospheric temperature rises, the ocean becomes warmer because it absorbs some of the heat.

According to the EPA, the oceans are now warmer than at any time over the last half century. These temperature changes affect the surface of the ocean and scientists suggests that the temperatures get warmer by 0.2 degrees Fahrenheit every decade. This seems like a small number but that means that the ocean temperatures are one degree warmer on average today than they were in the 1950s. For a huge body of water like the Pacific Ocean, this one degree makes a huge difference.

Because warmer atmospheres can hold more rain, the warmer temperatures in general cause more frequent and more violent weather than before.

  1. Every Couple of Years, the Winds from the Pacific that Usually Blow from East to West get Weaker

How El Nino looks compared to a normal year.
How El Nino looks compared to a normal year.

Most of the time, the Pacific Ocean boasts strong winds that blow from east to west. These winds are called trade winds. These winds do not just blow ships or clouds, they blow the ocean water from east to west as well.

In a normal year, all of the warm water from the equator is blown towards Indonesia where about half a meter of water is piled up. This means that the western part of the ocean has more warm water and the eastern part of the Pacific, near South America, has colder water. The water in Indonesia is around 30 degrees Celsius in Asia and around 22 degrees Celsius near Peru and South America.

For some reason, the trade winds are weaker every few years. When the winds are weak, the warm water in the western ocean begins to move back towards the east. Instead of remaining piled up near Asia, it begins to spread out again towards South America. This makes the warmer in the eastern part of the ocean warmer. This warm water near South America is one of the distinguishing features of an El Nino.

These changes create a vicious cycle of weather. The warmer the ocean is, the weaker the winds get. When the winds get weaker, the ocean gets warmer. As this cycle continues, the El Nino season becomes more powerful.

  1. Scientists Don’t Know What Triggers Each Individual El Nino

Even scientist are puzzled by the El Nino weather phenomenon
Even scientist are puzzled by the El Nino weather phenomenon

El Nino only comes every three to seven years and when it arrives, the season varies. Some cycles have been destructive while others have just brought extra rain to areas that desperately need it. Although scientists can predict when an El Nino is about to occur, it is impossible to predict them years in advance or to establish any kind of pattern.

El Nino is most often predicted by the measurement of ocean water temperatures, the winds and by scientists who study waves. There are certain conditions that need to be met for an El Nino to be formed but no one is sure what the catalyst is for the weather pattern.

Part of the reason that scientists have not yet discovered the root of El Nino is because it happens so infrequently compared to other types of weather. Thunderstorms happen year round across the world. Hurricanes, cyclones and typhoons are also relatively common. But, El Nino only happens every few years on average. This timeline combined with the fact that scientists have only had the necessary tools to study this phenomenon in the Pacific ocean for around 20 years means that it is not as easy to understand as more common weather patterns.

Scientists’ predictions have also been wrong in the past. The conditions have looked right for the world to see the worst El Nino on record but it was much milder than expected. In some cases, a predicted El Nino never appeared at all.

  1. The Ocean’s Waves Have an Effect on El Nino

Waves. Not just for surfing. They play an important part in El Nino's development.
Waves. Not just for surfing. They play an important part in El Nino’s development.

On the shore, most people can’t distinguish between most types of waves. Most of the kinds of waves that occur in the ocean happen far out at sea where people won’t see them unless they’re making an ocean passage.

One wave in particular has an effect on El Nino conditions. This wave is called the Rossby wave. The Rossby wave has similar properties to a tidal wave. The main difference between a Rossby wave and a tidal wave is that tidal waves move quickly whereas the Rossby wave takes a more leisurely pace.

In a tidal wave, all of the water will move in the same direction quickly. A Rossby wave is difference because the top 100 meters of the ocean will form a wave and will slowly slide one way while another 100 meters below will move the other way. The two parts will switch directions after a while but you can’t see it because it happens underneath the surface of the ocean. This wave moves so slowly that it can take years for the wave to make it all the way across the ocean. However, the waves can be thousands of kilometers long, so their movement has an effect on the ocean conditions no matter how slowly it moves.

El Nino often starts with a wave. This wave is similar to the Rossby wave, and it is called the Kelvin wave. The Kelvin wave moves a little bit faster than a Rossby wave and it only occurs within close proximity to the equator. The Kelvin wave that triggers an El Nino will usually start around the equator in the western Pacific Ocean, and then move toward the east and South America.

When El Nino begins approaching the eastern region of the Pacific Ocean, it then creates the slow moving Rossby waves. These waves move backwards towards Asia. After the wave reaches South East Asia, it reflects the conditions back. Instead of sending El Nino conditions to Asia, these waves bring warm water that cancel out any effects of the El Nino.

Because of this slow moving process, scientists can predict an El Nino as far as 12 to 18 months in advance.

  1. Each Season Might Bring a Strong El Nino or it May Bring a Weak El Nino

El Nino 2015: predicted to be one of the strongest ever!
El Nino 2015: predicted to be one of the strongest ever!

The strength of the El Nino season usually depends partly on how far east the pool of warm water is able to move. It is also dependent on the amount of warm water in the Pacific Ocean. After several decades of monitoring this phenomenon, scientists can sometimes predict the strength of El Nino based on water measurements.

However, these predictions are not always accurate. Scientists have previously predicted El Ninos that never materialized. They have also predicted for an El Nino to be the worst season on record but it never lived up to expectations.
Because scientists do not have a full understanding of the phenomenon itself, it is hard to be able to predict precisely what kind of El Nino the world might experience during any given cycle. This is why predictions may sometimes fail to materialize.

  1. El Nino and La Nina are on Two Different Ends of the Oscillation Sphere

La Nina compared to a normal year.
La Nina compared to a normal year.

As discussed earlier, El Nino forms when warm water pools up in the western Pacific Ocean and is then moved to the east. El Nino is affected by weak trade winds that often reverse their direction to move warm water from its usual home near Asia to the Galapagos.

La Nina is what happens when the water in the Pacific is cooler than usual in the eastern part of the ocean. When a La Nina occurs, the winds actually get stronger. This means that the warm water near South America is blown back towards Asia and cold water comes in to replace the lost warm water.

The effects of La Nina are also different than El Nino. While El Nino brings flooding to North and South America, La Nina will feature drier conditions in the southern part of America and

  1. El Nino can Disrupt the Biosphere

No food?! I hate El Nino!
No food?! I hate El Nino!

El Nino can completely disrupt the ocean’s biosphere and even our biosphere on land by extension. The neutral temperatures of the ocean help keep the nutrients alive and moving. Most of the known animals in the sea depend heavily on these nutrients as a source of food.

One of the creatures in the sea that depends very heavily on these nutrients is called phytoplankton. Phytoplankton depends on both the sun and the food from the sea to remain alive. Although they are small and uncomplicated organisms, a good portion of the fish and sea life depend on phytoplankton as their main source of food. Even whales consume phytoplankton as one of their main sources of nutrition. Without phytoplankton, many fish and animals in the ocean die of starvation.

The worse the El Nino season is, the more the animals and seal life suffer. For example, in the 1982-83 El Nino season, sea birds were forced to fly over huge amounts of oceans to find food and had to abandon their nests and their young.

In Peru, almost 25 percent of both the seal and the sea lion populations perished from starvation. Although only 25 percent of the adults died, this resulted in the death of almost every seal and sea lion pup that was born that year. Without adults to help protect and feed them, the pups could not take care of themselves and the result was a high level of mortality amount the young animals.

Fisherman also reported that their daily catches were nearly impossible because of a dramatic decline in the number of fish in their prime fishing areas.

During an El Nino year, the state of California will often see warmer ocean temperatures because of the warm southern waters near South America. This change in temperature also disrupts life for California’s typical marine species. Any fish or seal life that cannot handle the change in temperature will either die or migrate north in search of cooler temperatures.

Other marine life from Mexico may also migrate towards California in a similar attempt to find cooler temperatures. These new types of sea life also change the ocean environment on the California coast. However, when the temperatures grow cooler and return to normal, many of these changes revert back to the way they were before El Nino.

  1. Is El Nino Our Fault?

Is El Nino caused by people?
Is El Nino caused by people?

El Nino is a fact of life on Earth. Even though humans contribute significantly to the global temperature changes in the atmosphere, the world would still experience the El Nino phenomenon. The Pacific Ocean is so large and so unstable that El Nino would probably be a reality even if humans were not around to record it.

However, to say that humans do not have an impact on El Nino would be incorrect. As humans continue to contribute to rising temperatures in the atmosphere, the El Ninos experienced have become not only more frequent but more violent. In a recent paper published by scientists, it was suggested that El Nino will continue to get worse as long as climate change is a major issue on Earth.

The cost of climate change on El Nino can be measured in billions of dollars every season. One of the worst El Ninos on record happened in 1997 and 1998. It is suggested to have cost the equivalent of $35-45 billion in damage across the globe. It is also suggested to have taken at least 23,000 lives.

  1. El Nino Affects Every Region Differently

The El Nino Phenomenon explained in a nice little graphic
The El Nino Phenomenon explained in a nice little graphic

Although the El Nino takes place in the equatorial regions and often lands off the cost of Ecuador and Peru, regions all over the world can feel the effects that this massive front can bring. However, not everyone experiences El Nino the same way. El Nino does not just have an impact on local weather, it can cause global floods and global famines that can even result in local or regional wars.

Although many talk about the effects of El Nino in South America, the first region to experience the phenomenon is often India. India depends on its monsoon reason to raise the crops it needs to feed its 1 billion and growing population. El Nino often weakens the monsoon rains in the region and this has a dramatic effect on the farming and food supplies in the country.

El Nino also often causes serious droughts across the Australian continent.

When El Nino hits South America, the warm weather kills fish and sea life which in turn leads to a collapse in the fishing economies that important to countries like Ecuador and Peru

El Nino can have devastating effects on one region while bringing the rain that another desperately needs. Many scientists hope that the 2015 El Nino will help relieve the intense period of drought in California. As huge fires blaze across the western coast of the United States, scientists, governments and residents hope that the rains will come soon.

El Nino also lowers the risk of hurricanes for the Atlantic Ocean. This is one of the few benefits of El Nino for the eastern United States. However, it also dramatically increases the odds of the Pacific Oceans experience typhoons and cyclones.


El Nino is one of the most elusive weather phenomena that happens on Earth. It is a completely natural weather pattern and it would continue to happen even if there were no scientists on Earth to record it or people to experience it.

El Nino is the product of several geographical conditions lining up to create the perfect storm. From atmospheric temperatures to ocean waves to changing winds, an El Nino is a complicated weather pattern that seems easy to predict but is hard to understand.

Despite their best attempts, scientists cannot definitively predict El Nino. Although they can see the conditions ripening a year in advance, they cannot definitively say that an El Nino will occur that year.

It is important for people to work to understand El Nino because it is more than just a wet winter in Los Angeles. The effects of El Nino are widespread and can be devastating. El Nino does more than just cause rain and droughts, El Nino causes inclement weather that can result in food shortages all over the world. The effect that it has on our physical world can change the price of gold or even start a war.

As long as humans live on Earth, they will continue to experience El Nino. However, as long as humans continue to pollute the Earth and contribute to rising atmospheric temperatures, the El Ninos that they experience will become worse and worse.

Instead of trying to prepare for a monster El Nino, perhaps humans could also work to understand how to stop these Godzilla storms from continuing to grow in the first place.