We explained what El Niño is and how it acts on our planet's weather system, as well as its contribution to marine ecosystems, so now let's turn our attention to the other weather phenomenon that is just as important for the planet's climate balance.

What is La Niña and how it occurs

Trade winds, which work in a similar way to El Niño and La Niña, blowing westward from the Americas to Australia and Asia, pushing the warm surface water with them. These trade winds cause the sea levels to rise naturally by about 0.5 meters and to get around 7.2 degrees Celsius warmer towards the west when they are in effect, while colder water rises on the coasts of Chile and Peru, a process known as upwelling.

This allows the oceanic nutrients to get towards the surface, where phytoplankton feeds off it and attracts natural predators, such as fish or marine mammals. Upwelling influences the climate of the planet as a whole, as the warmer air that moves towards Asia causes the heavy rainfall that happens during the annual monsoon season.

Both El Niño and La Niña are weather patterns that happen in the Pacific Ocean and that disrupt this phenomenon.

Also known as anti-El Niño, La Niña is the event that brings cold ocean currents, instead of warm ones, having the opposite effect. The difference is that, during La Niña, the trade winds get significantly stronger, pushing even more hot air towards Eastern Asia, while on the coast of the Americas, the upwelling becomes more intense, bringing the cold and nutrient-rich water to the surface.

What are the effects of La Niña on the planet's climate system

This has a broader effect on Earth's climate, as the cold waters push the jet stream in the Pacific to the North, leading to droughts in Southern US states, while bringing heavy rainfall and floodings in the Pacific Northwest and Canada.

Just like El Niño, La Niña can last anywhere from 9 to 12 months, but it's not unusual for these to extend on multiple years. When La Niña manifests, temperatures in winter tend to rise in the South, while in the North, they drop more than normal.

Experts at National Geographic say that, during the 1988-1989 La Niña event, coastal sea-surface temperatures near Ecuador and Peru dropped by almost 4 degrees Celsius.

At the same time, in years when La Niña is in full force, hurricanes can also become more intense. Because the upwelling brings more cold water to the surface, there are also more nutrients for marine wildlife to feed off of, meaning that La Niña is actually a blessing for species such as salmon and squids, which are looking for feeding opportunities off the coast of California.

But the effects go beyond the Pacific Ocean, as La Niña brings more rainfall than usual in Brazil and in Africa, as well

Today, scientists, governments and even NGOs study the effects and behaviors of both El Niño and La Niña, using multiple technologies, such as buoys, which measure ocean and air temperatures, as well as winds and humidity. The National Oceanic and Atmospheric Administration (NOAA) has a network of 70 such buoys, which span from the Galapagos Islands all the way to Australia.

Using the data sent daily from these buoys, as well as satellite imagery, researchers are able to more accurately predict how La Niña behaves, while assessing the potential impact it has on the planet.

Currently, there is no scientific agreement on whether or not these weather effects are affected by climate change or how much they are influenced by these changes, but researchers study their behavior continuously to discover the correlation between human-induce global warming and the ocean currents.