El Nino and La Nina

By : Neha Dhyani

Updated : May 20, 2022, 5:21

Normally trade winds blow west along the equator, in the Pacific Ocean, carrying warm water from South America to Asia which is replaced by cold water rising from below. This is a process called upwelling.

El Nino and La Nina are two conflicting climate patterns that disrupt this pattern and result in global effects on ecosystems, weather, wildfires, and the economy. El Nino and La Nina episodes usually occur every two to seven years (not consistent), and last 9-12 months, in some cases several years. In general, El Nino occurs more often than La Nina. El Nino and La Nina are complex weather patterns, that can occur as a result of fluctuations in ocean temperature in the eastern central equatorial Pacific.

This can lead to extreme weather events like floods, heavy rains, and severe droughts in many parts of the world.

What is El Nino?

During El Nino, the trade winds weaken, and warm water is pushed back towards the west coast of the United States. The full name is El Nina de Navidad, as it typically heightens around December. El Nino means little boy or the child of Christ in Spanish. It was first observed in the 16th century by South American fishermen during the unusually warm waters of the Pacific Ocean.

El Nino can have a significant impact on the weather. Warm water moves the Pacific jet stream south from its neutral position. This shift makes the northern United States and Canada regions drier and warmer than usual. On the other hand, these periods can cause more heavy rainfall than usual, leading to increased floods in the Gulf and southeastern United States.

El Nino also has a strong impact on the marine life of the Pacific coast. Under normal circumstances, upwelling carries water, that is cold and rich in nutrients, from the deep to the surface. El Nino weakens or stops the upwelling that can cause a dearth of nutrient-rich water on which the offshore phytoplankton thrive. This further leads to the destruction of the food chain in the ocean.

☛ Also Read: Current Affairs Today

What is La Nina?

It means little girl in Spanish and is also referred to as El Viejo, Anti El Nina, or a "cold event". La Nina contradicts El Nino. During the La Nina phenomenon, trade winds are stronger than push warmer water into Asia. Upwelling increases off the west coast of the United States, bringing nutrient-rich cold water to the surface.

These cold waters of the Pacific Ocean drive the jet stream north and cause droughts in the southern United States and heavy rains and floods in the Pacific Northwest and Canada.

Winter temperatures are warmer in the south and cooler in the north. La Nina can also lead to hurricanes. The waters off the Pacific coast are colder than normal and contain more nutrients supporting more marine life and attracting more coldwater species such as squid and salmon to places like the California coast.

Important UPSC Topics
UPSC ExamUPSC Exam Date
UPSC NotificationUPSC Eligibility
UPSC Online ApplicationUPSC Exam Pattern
UPSC SyllabusUPSC Previous Year Question Papers
UPSC Cut OffUPSC Preparation Strategy
UPSC BooksUPSC Exam Analysis
UPSC Admit CardUPSC Results

Important to Monitor El Nino and La Nina

Both El Nino and La Nina are part of a natural cycle that can have significant impacts not only on global weather, climate, and marine conditions but also on food production, human health, and water supply. These systems usually last about 1 to 2 years and the cycle changes every 3 to 7 years.

According to National Oceanic and Atmospheric Administration - NOAA's forecast, the United States will experience warmer and drier conditions in the southeast and cooler and damp conditions in the north. The NOAA Climate Prediction Center is also closely monitoring the ongoing drought, as nearly half of the continental United States can suffer from the driest conditions.

More Current Affairs Topics
Difference Between Written and Unwritten ConstitutionEase of Doing Business
E-Waste Management Rules 2016Early Medieval India
East African Community [EAC]Economic Empowerment
Economic and Social Council [ECOSOC]Egypt on Non-Aligned Movement
Ek Bharat Shreshtha Bharat SchemeEka Movement

FAQs on El Nino and La Nina

Q.1. In the Content of El Nino and La Nina, How was El Nino discovered?

In the Content of El Nino and La Nina, El Nino was first recognized as unusually warm water by Peruvian fishermen off the coast of Peru and was named by Spanish immigrants which means "little boy".

Q.2. In the Content of El Nino and La Nina, What was the effect of La Nina that occurred in 2010?

In the Content of El Nino and La Nina, The 2010 La Nina phenomenon correlated with one of the worst floods in Queensland in Australian history. It resulted in the evacuation of more than 10,000 people with damage caused by the disaster estimated to be more than US $2 billion.

Q.3. Can you predict El Nino and La Nina?

Yes, scientists can forecast El Nino and La Nina outbreaks several months-1 years before it occurs using the latest climate models and observational data like satellite sensors and sea buoy sensors) that constantly monitor changing conditions in the ocean and atmosphere.

Q.4. In the Content of El Nino and La Nina, Does La Nina always follow El Nino?

In the Content of El Nino and La Nina, La Niña episodes can follow El Nino, but not necessarily.

Q.5. In the Content of El Nino and La Nina, How often do El Nino and La Nina occur?

In the Content of El Nino and La Nina, The occurrence moves back and forth between the El Nino and La Nina stages on average every 3-7 years.

Q.6. In the Content of El Nino and La Nina, When was the last El Nino episode?

In the Content of El Nino and La Nina, The last episode of El Nino started in 2015 and was marked as one of the three strongest El Nino episodes on record.