What causes the El Nino Southern Oscillation pattern?

Although the exact initiating causes of an ENSO warm or cool event are not fully understood, the two components of ENSO – sea surface temperature and atmospheric pressure are strongly related. During an El Niño event, the easterly trade winds converging across the equatorial Pacific weaken.

Moreover, what is the Southern Oscillation?

The Southern Oscillation is the atmospheric component of a single large-scale coupled interaction called the El Niño/Southern Oscillation (ENSO).

What is the meaning of ENSO?

“ENSO” refers to the El Niño/Southern Oscillation, the interaction between the atmosphere and ocean in the tropical Pacific that results in a somewhat periodic variation between between below-normal and above-normal sea surface temperatures and dry and wet conditions over the course of a few years.

What is the El Nino effect?

An El Niño is a temporary change in the climate of the Pacific ocean, in the region around the equator. You can see its effects in both the ocean and atmosphere, generally in Northern Hemisphere winter. Typically, the ocean surface warms up by a few degrees celsius.

How does El Nino affect the United States?

During El Niño, the jet stream is oriented from west to east across the southern portion of the United States, making the region more susceptible to severe weather outbreaks. During La Niña, the jet stream and severe weather are likely to be farther north than normal.

What are the causes and effects of La Nina?

La Niña is caused by a build-up of cooler-than-normal waters in the tropical Pacific, the area of the Pacific Ocean between the Tropic of Cancer and the Tropic of Capricorn. Unusually strong, eastward-moving trade winds and ocean currents bring this cold water to the surface, a process known as upwelling.

How does El Nino affect people’s lives?

El Niño affects more than 60 million people. Severe drought and associated food insecurity, flooding, rains, and temperature rises due to El Niño are causing a wide range of health problems, including disease outbreaks, malnutrition, heat stress and respiratory diseases.

Why is it important to know about El Nino?

El Niño is part of a periodic oceanic weather phenomenon known as the Southern Oscillation. An understanding of El Niño is important for two reasons: 1) it is a useful model for predicting both long and short term climate changes, 2) it impacts global economies and ecologies.

What is the phenomenon of El Niño?

El Niño is a climate pattern that describes the unusual warming of surface waters in the eastern tropical Pacific Ocean. El Nino is the “warm phase” of a larger phenomenon called the El Nino-Southern Oscillation (ENSO). El Niño events occur irregularly at two- to seven-year intervals.

What is the Southern Oscillation?

The Southern Oscillation is the atmospheric component of a single large-scale coupled interaction called the El Niño/Southern Oscillation (ENSO).

How are El Nino sea surface temperatures and weather conditions different from normal conditions?

During an El Niño, the trade winds weaken in the central and western Pacific. Surface water temperatures off South America warm up, because there is less upwelling of the cold water from below to cool the surface. The clouds and rainstorms associated with warm ocean waters also shift toward the east.

What is the meaning of ENSO?

“ENSO” refers to the El Niño/Southern Oscillation, the interaction between the atmosphere and ocean in the tropical Pacific that results in a somewhat periodic variation between between below-normal and above-normal sea surface temperatures and dry and wet conditions over the course of a few years.

What is the the Southern Oscillation Index?

The Southern Oscillation Index, or SOI, gives an indication of the development and intensity of El Niño or La Niña events in the Pacific Ocean. The SOI is calculated using the pressure differences between Tahiti and Darwin.

Where does the El Nino occur?

El Niño is an unusual warming of the tropical Pacific Ocean that occurs irregularly at about 3-6 year intervals in response to large scale weakenings of the trade winds that normally blow westward from South America toward Asia.

Which weather conditions are associated with El Nino?

El Niño Southern Oscillation refers to the cycle of warm and cold temperatures, as measured by sea surface temperature, SST, of the tropical central and eastern Pacific Ocean. El Niño is accompanied by high air pressure in the western Pacific and low air pressure in the eastern Pacific.

How does El Nino affect the economies of Ecuador and Peru?

This allows cool water to well up around the coast of South America. The cool water is rich in nutrients and fish, providing rich pickings for the Peruvian fishing industry. During an El Nino year, however, the winds, which blow along the surface of the tropical Pacific Ocean, ease.

Why do El Nino and La Nina occur?

El Niño happens when tropical Pacific Ocean trade winds die out and ocean temperatures become unusually warm. There is a flip side to El Niño called La Niña, which occurs when the trade winds blow unusually hard and the sea temperature become colder than normal.

What does Enso stand for and what is it?

El Niño Southern Oscillation

What is the Walker circulation?

The Walker circulation, also known as the Walker cell, is a conceptual model of the air flow in the tropics in the lower atmosphere (troposphere). According to this model, parcels of air follow a closed circulation in the zonal and vertical directions.

How does the El Nino affect climate?

El Niño is the periodic warming of water in the Pacific Ocean every few years. When it occurs, it means more energy is available for storms to form there. El Niño also affects wind shear, which is when air currents at a lower altitude blow in a different direction from winds higher in the atmosphere.

How does El Nino affect the fishing industry?

An El Niño reduces the upwelling of cold water off the coast of the Americas. When this happens, fish either die or migrate into areas where they’ll find more to eat. With the fish gone, sea birds that depend on them may die or go elsewhere. Kelp forests are often destroyed by storms and ocean swells.

How long does Enso last?

El Ni o typically lasts 9-12 months, and La Ni a typically lasts 1-3 years. They both tend to develop during March-June, reach peak intensity during December-April, and then weaken during May-July. However, prolonged El Ni o episodes have lasted 2 years and even as long as 3-4 years.

Leave a Comment