Where is El Niño located? Climate phenomena La Niña and El Niño and their impact on health and society. The natural phenomenon of El Niño

Fires and floods, droughts and hurricanes all hit our Earth together in 1997. The fires turned the forests of Indonesia to ashes, then raged across the expanses of Australia. Downpours are frequent over the Chilean Atacama Desert, which is particularly dry. heavy rains, the floods did not spare South America either. The total damage from the willfulness of the elements amounted to about 50 billion dollars.

The cause of all these disasters, meteorologists believe the phenomenon of El Niño.

The term "El Niño" was first used in 1892 at the congress of the Geographical Society in Lima. Captain Camilo Carrilo reported that Peruvian sailors gave the name "El Niño" to the warm northern current, as it is best seen on Catholic Christmas. In 1923, Gilbert Thomas Walker began to study the zonal convection circulation of the atmosphere in the equatorial zone of the Pacific Ocean and introduced the terms "Southern Oscillation", "El Niño" and "La Niña". Until the end of the 20th century, his work remained known only in narrow circles, until the connection between El Niño and the planet's climate change was established.

El Niño means "baby" in Spanish. This affectionate name only reflects the fact that El Niño most often begins around the Christmas holidays, and the fishermen of the west coast of South America associated it with the name of Jesus in infancy.

In normal years, along the entire Pacific coast of South America, due to the coastal rise of cold deep waters caused by the surface cold Peruvian current, the ocean surface temperature fluctuates within narrow seasonal limits - from 15°C to 19°C. During the El Niño period, the ocean surface temperature in the coastal zone rises by 6-10°C. As evidenced by geological and paleoclimatic studies, the mentioned phenomenon exists for at least 100 thousand years. Fluctuations in the temperature of the surface layer of the ocean from extremely warm to neutral or cold occur with periods of 2 to 10 years. Currently, the term "El Niño" is used in relation to situations where abnormally warm surface waters occupy not only the coastal region near South America, but also most of tropical zone Pacific Ocean up to 180 meridian.

There is a constant warm current, originating from the coast of Peru and stretching to the archipelago lying southeast of the Asian continent. It is an elongated tongue of heated water, equal in area to the territory of the United States. The heated water evaporates intensively and "pumps" the atmosphere with energy. Clouds form over the warm ocean. Usually trade winds (constantly blowing east winds in the tropical zone) drive a layer of this warm water from the American coast towards Asia. Approximately in the region of Indonesia, the current stops, and monsoon rains pour over southern Asia.

During El Niño near the equator, this current warms up more than usual, so the trade winds weaken or do not blow at all. The heated water spreads to the sides, goes back to the American coast. Arises anomalous zone convection. Rains and hurricanes hit Central and South America. Over the past 20 years, there have been five active El Niño cycles: 1982-83, 1986-87, 1991-1993, 1994-95 and 1997-98.

The La Niño phenomenon, the opposite of El Niño, manifests itself as a drop in surface water temperature below the climatic norm in the eastern tropical Pacific. Such cycles were observed in 1984-85, 1988-89 and 1995-96. Unusually cold weather established in the eastern Pacific during this period. During the formation of La Niño, the trade winds (east) winds from the west coast of both Americas increase significantly. The winds shift the zone of warm water and the "language" of cold waters stretches for 5000 km, exactly in the place (Ecuador - Samoa Islands), where during El Niño there should be a belt of warm waters. During this period, powerful monsoon rains are observed in Indochina, India and Australia. The Caribbean and the United States suffer from droughts and tornadoes. La Niño, like El Niño, most often occurs from December to March. The difference is that El Niño occurs on average once every three to four years, while La Niño occurs once every six to seven years. Both phenomena bring with them an increased number of hurricanes, but during La Niño there are three to four times more than during El Niño.

According to recent observations, the reliability of the onset of El Niño or La Niño can be determined if:
1. At the equator, in the eastern part of the Pacific Ocean, a patch of warmer water than usual (El Niño), colder (La Niño) is formed.
2. The atmospheric pressure trend between the port of Darwin (Australia) and the island of Tahiti is compared. With El Niño, pressure will be high in Tahiti and low in Darwin. With La Niño, the opposite is true.

Research over the past 50 years has established that El Niño means more than just the coordinated fluctuations in surface pressure and ocean water temperature. El Niño and La Niño are the most pronounced manifestations of interannual climate variability on a global scale. These phenomena are large-scale changes in ocean temperatures, precipitation, atmospheric circulation, and vertical air movements over the tropical Pacific.

Abnormal weather conditions on the globe during El Niño years

In the tropics, there is an increase in precipitation over areas east of the central Pacific and a decrease from the norm over northern Australia, Indonesia and the Philippines. In December-February, more than normal precipitation is observed along the coast of Ecuador, in northwestern Peru, over southern Brazil, central Argentina and over the equatorial, eastern part Africa, during June-August in the western United States and over the central part of Chile. El Niño events are also responsible for large-scale air temperature anomalies around the world. During these years, there are outstanding temperature rises. Warmer than normal conditions in December-February were above southeast Asia, over Primorye, Japan, Sea of Japan, over southeast Africa and Brazil, southeast Australia. Warmer than normal temperatures occur in June-August along the west coast of South America and over southeastern Brazil. Colder winters (December-February) are southwest coast USA.

Abnormal weather conditions on the globe during the La Niño years

During La Niño periods, precipitation increases over the western equatorial Pacific, Indonesia and the Philippines and is almost completely absent in the eastern part. More precipitation falls in December-February over northern South America and over South Africa, and in June-August over southeastern Australia. Dryer-than-normal conditions occur over the coast of Ecuador, over northwest Peru and equatorial east Africa during December-February, and over southern Brazil and central Argentina in June-August. There are large-scale deviations from the norm around the world with the most big amount areas experiencing abnormally cool conditions. Cold winters in Japan and in Primorye, over southern Alaska and western, central Canada. Cool summer seasons over southeast Africa, over India and southeast Asia. Warmer winters over the US Southwest.

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El Niño

Southern Oscillation And El Niño(Spanish) El Nino- Kid, Boy) is a global ocean-atmospheric phenomenon. Being feature Pacific Ocean, El Niño and La Niña(Spanish) La Nina- Baby, Girl) are temperature fluctuations in surface water in the tropics of the eastern Pacific Ocean. The names of these phenomena, borrowed from Spanish local residents and first introduced into scientific circulation in 1923 by Gilbert Thomas Walker, mean "baby" and "baby", respectively. Their influence on the climate of the southern hemisphere is difficult to overestimate. The Southern Oscillation (atmospheric component of the phenomenon) reflects monthly or seasonal fluctuations in the difference in air pressure between the island of Tahiti and the city of Darwin in Australia.

Named after Walker, the circulation is an essential aspect of the Pacific ENSO (El Niño Southern Oscillation) phenomenon. ENSO is a set of interacting parts of one global system of ocean-atmospheric climate fluctuations that occur as a sequence of oceanic and atmospheric circulations. ENSO is the world's best-known source of interannual weather and climate variability (3 to 8 years). ENSO has signatures in the Pacific, Atlantic and Indian Oceans.

In the Pacific, during significant El Niño warm events, as it warms up, it expands over much of the Pacific tropics and becomes directly related to the intensity of the SOI (Southern Oscillation Index). While ENSO events are found primarily between the Pacific and Indian Oceans, ENSO events in Atlantic Ocean lagging behind the first by 12-18 months. Most of the countries that are subject to ENSO events are developing countries, with economies heavily dependent on the agricultural and fishing sectors. New opportunities to predict the onset of ENSO events in three oceans could have global socio-economic implications. Since ENSO is a global and natural part of the Earth's climate, it is important to know if the change in intensity and frequency could be the result of global warming. Low frequency changes have already been detected. Inter-decadal ENSO modulations may also exist.

El Niño and La Niña

El Niño and La Niña are officially defined as long-term marine surface temperature anomalies greater than 0.5 °C across the Pacific Ocean in its central tropical region. When a +0.5 °C (-0.5 °C) condition is observed for up to five months, it is classified as an El Niño (La Niña) condition. If the anomaly persists for five months or longer, then it is classified as an El Niño (La Niña) episode. The latter occurs at irregular intervals of 2-7 years and usually lasts one or two years.

The first signs of El Niño are as follows:

Rising air pressure over the Indian Ocean, Indonesia and Australia.
Drop in air pressure over Tahiti and the rest of the central and eastern Pacific Ocean.
The trade winds in the South Pacific are weakening or heading east.
Warm air appears next to Peru, causing rain in the deserts.
Warm water spreads from the western part of the Pacific Ocean to the east. She brings rain with her, causing it in areas where it is usually dry.

The warm El Niño Current, composed of plankton-poor tropical water and heated by its eastern branch in the Equatorial Current, replaces the cold, plankton-rich waters of the Humboldt Current, also known as the Peruvian Current, which contains large populations commercial fish. Most years, warming lasts only a few weeks or months, after which weather patterns return to normal and fish catches increase. However, when El Niño conditions last several months, more extensive ocean warming occurs and its economic impact on local fisheries for the export market can be severe.

The Volcker circulation is visible on the surface as easterly trade winds, which move westward water and air heated by the sun. It also creates oceanic upwelling off the coast of Peru and Ecuador and cold waters rich in plankton flow to the surface, increasing fish stocks. The western equatorial part of the Pacific Ocean is characterized by warm, humid weather and low atmospheric pressure. The accumulated moisture falls out in the form of typhoons and storms. As a result, in this place the ocean is 60 cm higher than in its eastern part.

In the Pacific, La Niña is characterized by unusually cold temperatures in the eastern equatorial region compared to El Niño, which in turn is characterized by unusually high temperature in the same region. Atlantic tropical cyclone activity in general case intensifies during La Niña. The La Niña condition often occurs after El Niño, especially when the latter is very strong.

Southern Oscillation Index (SOI)

The Southern Oscillation Index is calculated from the monthly or seasonal fluctuations in the air pressure difference between Tahiti and Darwin.

Long negative values SOI often signal episodes of El Niño. These negative values are usually associated with prolonged warming in the central and eastern tropical Pacific Ocean, a decrease in the strength of the Pacific trade winds and a decrease in precipitation in the east and north of Australia.

Positive SOI values are associated with strong Pacific trade winds and warming water temperatures in northern Australia, well known as the La Niña episode. The waters of the central and eastern tropical Pacific become colder during this time. Together, all of this increases the likelihood of more rainfall in eastern and northern Australia than usual.

Extensive influence of El Niño conditions

As El Niño's warm waters fuel storms, this creates an increase in rainfall in east-central and eastern parts Pacific Ocean.

IN South America El Niño effect is more pronounced than in North America. El Niño is associated with warm and very wet summers (December-February) along the coasts of northern Peru and Ecuador, causing severe flooding whenever the event is strong. Effects during February, March, April can become critical. Southern Brazil and northern Argentina also experience wetter than normal conditions, but mostly during the spring and early summer. Central Region of Chile receives mild winter with a lot of rain, and the Peruvian-Bolivian Plateau sometimes experiences unusual winter snowfalls for this region. more dry and warm weather observed in the Amazon Basin, Colombia and Central America.

The direct effects of El Niño lead to a decrease in humidity in Indonesia, increasing the likelihood of wildfires in the Philippines and northern Australia. Also in June-August, dry weather is observed in the regions of Australia: Queensland, Victoria, New South Wales and eastern Tasmania.

The west of the Antarctic Peninsula, Ross Land, the Bellingshausen and Amundsen seas are covered with large amounts of snow and ice during El Niño. The latter two and the Wedell Sea are getting warmer and under higher atmospheric pressure.

In North America, winters tend to be warmer than usual in the Midwest and Canada, while it is getting wetter in central and southern California, northwestern Mexico, and the southeastern United States. The Pacific Northwest states, in other words, are drained during El Niño. Conversely, during La Niña, the US Midwest dries up. El Niño is also associated with a decrease in Atlantic hurricane activity.

Eastern Africa, including Kenya, Tanzania and the White Nile Basin, experience prolonged rains from March to May. Droughts haunt the southern and central regions of Africa from December to February, mainly Zambia, Zimbabwe, Mozambique and Botswana.

Warm Basin of the Western Hemisphere

A study of climate data showed that about half summer periods after El Niño there is an unusual warming of the Western Hemisphere Warm Basin. This affects the weather in the region and seems to be related to the North Atlantic Oscillation.

Atlantic effect

An El Niño-like effect is sometimes observed in the Atlantic Ocean, where the water along the African equatorial coast is getting warmer, while off the coast of Brazil it is getting colder. This can be attributed to the Volcker circulations over South America.

Non-climatic effects

Along east coast South America's El Niño reduces the upwelling of cold, plankton-rich water that supports large fish populations, which in turn support an abundance of seabirds whose droppings support the fertilizer industry.

The local fishing industry along the coastline may be short of fish during long El Niño events. The largest global fish collapse due to overfishing, which occurred in 1972 during El Niño, led to a decrease in the population of Peruvian anchovies. During the events of 1982-83, populations of southern horse mackerel and anchovies decreased. Although the number of shells in warm water increased, but the hake went deeper into the cold water, and the shrimps and sardines went south. But the catch of some other fish species has been increased, for example, the common horse mackerel increased its population during warm events.

Changes in location and types of fish due to changing conditions have provided challenges for the fishing industry. The Peruvian sardine left due to El Nino to the Chilean coast. Other conditions have only led to further complications, such as the government of Chile in 1991 created restrictions on fishing.

It is postulated that El Niño led to the disappearance of the Mochico Indian tribe and other tribes of the pre-Columbian Peruvian culture.

Causes of El Niño

The mechanisms that can trigger El Niño events are still under investigation. It is difficult to find patterns that can show causes or allow predictions to be made.

History of the theory

The first mention of the term "El Niño" refers to the city, when Captain Camilo Carrilo told the congress Geographical Society in Lima, that the Peruvian sailors named the warm north current "El Niño", as it is most noticeable in the Christmas area. However, even then, the phenomenon was only interesting because of its biological impact on the efficiency of the fertilizer industry.

Normal conditions along the western Peruvian coast are a cold south current (Peruvian current) with upwelling water; upwelling of plankton leads to active ocean productivity; cold currents lead to a very dry climate on earth. Similar conditions exist everywhere (California Current, Bengal Current). So replacing it with a warm northern current leads to a decrease in biological activity in the ocean and to heavy rains, leading to flooding, on earth. A connection to flooding has been reported in Peset and Eguiguren.

Towards the end of the nineteenth century, interest arose in predicting climate anomalies (for food production) in India and Australia. Charles Todd suggested that droughts in India and Australia occur at the same time. Norman Lockyer pointed out the same in d. In d. Gilbert Walker was the first to coin the term "Southern Oscillation".

For most of the twentieth century, El Niño was considered a large local phenomenon.

The history of the phenomenon

ENSO conditions have happened every 2-7 years for at least the last 300 years, but most have been mild.

Big ENSO events occurred in - , , - , , - , - and -1998.

The last El Niño events occurred in -, -,,,, 1997-1998 and -2003.

The 1997-1998 El Niño in particular was strong and brought international attention to the phenomenon, while it was unusual for the 1997-1998 period that El Niño was very frequent (but mostly weak).

El Niño in the history of civilization

Scientists tried to establish why at the turn of the 10th century AD, at opposite ends of the earth, the two largest civilizations of that time almost simultaneously ceased to exist. We are talking about the Maya Indians and the fall of the Chinese Tang dynasty, followed by a period of internecine strife.

Both civilizations were located in monsoonal regions, the moistening of which depends on the seasonal precipitation. However, at the indicated time, apparently, the rainy season was not able to provide sufficient moisture for the development Agriculture.

The ensuing drought and subsequent famine led to the decline of these civilizations, the researchers believe. They link climate change to the natural phenomenon El Niño, which refers to temperature fluctuations surface waters of the eastern Pacific Ocean in tropical latitudes. This leads to large-scale disturbances in atmospheric circulation, which causes droughts in traditionally wet regions and floods in dry ones.

Scientists arrived at these conclusions by examining the nature of sedimentary deposits in China and Mesoamerica dating back to the specified period. The last emperor of the Tang Dynasty died in 907 AD, and the last known Mayan calendar dates from 903.

Literature

Cesar N. Caviedes, 2001. El Nino in History: Storming Through the Ages(University Press of Florida)
Brian Fagan, 1999. Floods, Famines, and Emperors: El Niño and the Fate of Civilizations(Basic Books)
Michael H. Glantz, 2001. Currents of change, ISBN 0-521-78672-X
Mike Davis, Late Victorian Holocausts: El Niño Famines and the Making of the Third World(2001), ISBN 1-85984-739-0

Climate, Climatology
Changing of the climate	Paleoclimatology El Niño Geochemical carbon cycle Proterozoic glaciation, Ice Age, Little Ice Age Thermal Maximum (

Special phenomena (processes) are observed in the World Ocean, which can be considered as anomalous. These phenomena extend over vast water areas and are of great ecological and geographical significance. Such anomalous phenomena covering the ocean and atmosphere are El Niño and La Niña. However, one should distinguish between the course of El Niño and the phenomenon of El Niño.

El Niño current - a constant, small oceanic current off the northwestern coast of South America. It is traced from the Panama Bay area and follows south along the coasts of Colombia, Ecuador, Peru to about 5 0 S However, approximately once every 6-7 years (but it happens more or less often), the El Niño current spreads far to the south, sometimes to northern and even central Chile (up to 35-40 0 S). The warm waters of El Niño push the cold waters of the Peruvian-Chile current and coastal upwelling into the open ocean. The ocean surface temperature in the coastal zone of Ecuador and Peru rises to 21-23 0 C, and sometimes up to 25–29 0 C. The anomalous development of this warm current, which lasts almost half a year - from December to May and which usually appears by Catholic Christmas, was called "El Niño" - from the Spanish "El Niсo - baby (Christ)". It was first seen in 1726.

This purely oceanological process has tangible and often catastrophic ecological consequences on land. Due to the sharp warming of water in the coastal zone (by 8-14 0 C), the amount of oxygen is significantly reduced and, accordingly, the biomass of cold-loving species of phyto- and zooplankton, the main food of anchovies and other commercial fish in the Peruvian region. A huge number of fish either die or disappear from this area. Catches of Peruvian anchovy fall in such years by 10 times. Following the fish, the birds that feed on it also disappear. As a result of this natural disaster, South American fishermen are ruined. In previous years, the anomalous development of El Niño led to famine in several countries of the Pacific coast of South America at once. . In addition, during the passage of El Niño weather conditions are deteriorating sharply in Ecuador, Peru and northern Chile, where powerful downpours occur, leading to catastrophic floods, mudflows and soil erosion on the western slopes of the Andes.

However, the consequences of the anomalous development of the El Niño current are felt only on the Pacific coast of South America.

The main culprit of the weather anomalies that have become more frequent in recent years, which have covered almost all continents, is called El Niño/La Niña phenomenon, manifested in a significant change in the temperature of the upper layer of water in the eastern tropical part of the Pacific Ocean, which causes intense turbulent heat and moisture exchange between the ocean and the atmosphere.

Currently, the term "El Nino" is used in relation to situations where abnormally warm surface waters occupy not only the coastal region near South America, but also most of the tropical Pacific Ocean up to the 180th meridian.

Under normal weather conditions, when the El Niño phase has not yet arrived, the warm surface waters of the ocean are kept by easterly winds - trade winds - in the western zone of the tropical Pacific Ocean, where the so-called tropical warm basin (TTB) is formed. The depth of this warm water layer reaches 100-200 meters, and it is the formation of such a large reservoir of heat that is the main and necessary condition for the transition to the El Niño phenomenon. At this time, the temperature of the water surface in the west of the ocean in the tropical zone is 29-30°C, while in the east it is 22-24°C. This difference in temperature is explained by the rise of cold deep waters to the surface of the ocean off the western coast of South America. At the same time, a water area with a huge reserve of heat is formed in the equatorial part of the Pacific Ocean, and an equilibrium is observed in the ocean-atmosphere system. This is a situation of normal balance.

Approximately once every 3-7 years, the balance is disturbed, and the warm waters of the western Pacific Ocean basin move eastward, and a sharp increase in the temperature of the surface layer of water occurs in a vast area in the equatorial eastern part of the ocean. The El Niño phase begins, the beginning of which is marked by sudden squall westerly winds (Fig. 22). They change the usual weak trade winds over the warm western Pacific Ocean and prevent the rise of cold deep waters off the western coast of South America to the surface. The atmospheric phenomena associated with El Niño were called the Southern Oscillation (ENSO - El Niño - Southern Oscillation) because they were first observed in the Southern Hemisphere. Due to the warm water surface, an intense convective rise of air is observed in the eastern part of the Pacific Ocean, and not in the western part, as usual. As a result, the area heavy rains shifts from the western regions of the Pacific to the eastern. Rains and hurricanes hit Central and South America.

Rice. 22. Usual conditions and the onset of El Niño

Over the past 25 years, there have been five active El Niño cycles: 1982-83, 1986-87, 1991-1993, 1994-95 and 1997-98.

The mechanism of development of the phenomenon of La Niña (in Spanish La Niça - “girl”) - the “antipode” of El Niño is somewhat different. The La Niña phenomenon manifests itself as a decrease in the surface water temperature below the climatic norm in the east of the equatorial zone of the Pacific Ocean. Unusually cold weather sets in here. During the formation of La Niña, easterly winds from the west coast of the Americas increase significantly. The winds shift the warm water zone (TTB), and the “tongue” of cold waters stretches for 5000 kilometers in exactly the place (Ecuador - Samoa Islands) where the warm water belt should be during El Niño. This belt of warm waters is shifting to the west of the Pacific Ocean, causing powerful monsoon rains in Indochina, India and Australia. The Caribbean and the United States are suffering from droughts, hot winds and tornadoes.

La Niña cycles were observed in 1984-85, 1988-89 and 1995-96.

Although the atmospheric processes that develop during El Niño or La Niña mostly operate in tropical latitudes, their consequences are felt throughout the planet and are accompanied by environmental disasters: hurricanes and rainstorms, droughts and fires.

El Niño occurs on average once every three to four years, La Niña - once every six to seven years. Both phenomena bring with them an increased number of hurricanes, but during La Niña there are three to four times more than during El Niño.

The certainty of an El Niño or La Niña can be predicted if:

1. At the equator in the Eastern Pacific Ocean, an area of warmer water than usual (El Niño phenomenon) or colder water (La Niña phenomenon) is formed.

2. The atmospheric pressure trend between the port of Darwin (Australia) and the island of Tahiti (Pacific Ocean) is compared. With El Niño, pressure will be low in Tahiti and high in Darwin. With La Niña, it's the other way around.

Research has made it possible to establish that the El Niño phenomenon is not only simple coordinated fluctuations in surface pressure and ocean water temperature. El Niño and La Niña are the most pronounced manifestations of interannual climate variability on a global scale. These phenomena are large-scale changes in ocean temperature, precipitation, atmospheric circulation, vertical air movements over the tropical Pacific Ocean and lead to abnormal weather patterns on the globe.

El Niño years in the tropics experience an increase in precipitation over areas east of the central Pacific and a decrease in northern Australia, Indonesia and the Philippines. In December-February, more than normal precipitation is observed along the coast of Ecuador, in northwestern Peru, over southern Brazil, central Argentina and over equatorial, eastern Africa, during June-August in the western United States and over central Chile.

The El Niño phenomenon is also responsible for large-scale air temperature anomalies around the world.

During El Niño years, energy transfer to the troposphere of tropical and temperate latitudes increases. This is manifested in an increase in thermal contrasts between tropical and polar latitudes, and intensification of cyclonic and anticyclonic activity in temperate latitudes.

During the El Niño years:

1. Weakened Honolulu and Asian anticyclones;

2. The summer depression over southern Eurasia is filled, which is the main reason for the weakening of the monsoon over India;

3. More than usually developed winter Aleutian and Icelandic lows.

During La Niña years, precipitation intensifies over the western equatorial part of the Pacific Ocean, Indonesia, and the Philippines, and is almost completely absent in the eastern part of the ocean. Most precipitation falls in the north of South America, in South Africa and southeastern Australia. Dryer than normal conditions are found along the coast of Ecuador, northwest Peru and equatorial east Africa. Globally, there are large-scale temperature abnormalities with the largest number areas experiencing abnormally cool conditions.

Over the past decade, great progress has been made in the comprehensive study of the El Niño phenomenon. This phenomenon does not depend on solar activity, but is associated with features in the planetary interaction of the ocean and atmosphere. A relationship has been established between El Niño and the Southern Oscillation (El Niño-Southern Oscillation - ENSO) of surface atmospheric pressure in southern latitudes. This change in atmospheric pressure leads to significant changes in the system of trade winds and monsoon winds and, accordingly, surface ocean currents.

The phenomenon of El Niño is increasingly affecting the global economy. So, this phenomenon of 1982-83. provoked terrible downpours in the countries of South America, caused enormous losses, the economy of many states was paralyzed. The consequences of El Niño were felt by half of the world's population.

The strongest for the entire period of observations was El Niño in 1997-1998. It caused the most powerful hurricane in the history of meteorological observations that swept over the countries of South and Central America. Hurricane winds and downpours swept away hundreds of houses, entire areas were flooded, and vegetation was destroyed. In Peru, in the Atacama Desert, where it generally rains once every ten years, a huge lake has formed with an area of tens of square kilometers. Unusually warm weather has been recorded in South Africa, southern Mozambique, Madagascar, and in Indonesia and the Philippines, an unprecedented drought reigned, leading to forest fires. In India, there was virtually no normal monsoonal rainfall, while in dry Somalia, the amount of rainfall was much higher than normal. The total damage from the elements amounted to about 50 billion dollars.

El Niño of 1997-1998 significantly affected the average global air temperature of the Earth: it exceeded the usual one by 0.44°С. In the same year, 1998, the highest average annual air temperature was recorded on Earth for all the years of instrumental observations.

The collected data indicate the regularity of the occurrence of El Niño with an interval ranging from 4 to 12 years. The duration of El Nino itself varies from 6-8 months to 3 years, most often it is 1-1.5 years. In this great variability lies the difficulty in predicting the phenomenon.

The influence of the El Niño and La Niña climatic phenomena, and hence the number of adverse weather conditions on the planet, according to climatologists, will increase. Therefore, humanity must closely monitor these climatic phenomena and study them.

La Nina

Southern Oscillation And El Niño(Spanish) El Nino- Kid, Boy) is a global ocean-atmospheric phenomenon. As a feature of the Pacific Ocean, El Niño and La Niña(Spanish) La Nina- Baby, Girl) are temperature fluctuations in surface water in the tropics of the eastern Pacific Ocean. The names of these phenomena, borrowed from the Spanish language of the locals and first introduced into scientific circulation in 1923 by Gilbert Thomas Walker, mean "baby" and "baby", respectively. Their influence on the climate of the southern hemisphere is difficult to overestimate. The Southern Oscillation (atmospheric component of the phenomenon) reflects monthly or seasonal fluctuations in the difference in air pressure between the island of Tahiti and the city of Darwin in Australia.

In the Pacific, during significant El Niño warm events, as it warms up, it expands over much of the Pacific tropics and becomes directly related to the intensity of the SOI (Southern Oscillation Index). While ENSO events are mostly between the Pacific and Indian Oceans, ENSO events in the Atlantic Ocean lag behind the first by 12-18 months. Most of the countries that are subject to ENSO events are developing countries, with economies heavily dependent on the agricultural and fishing sectors. New opportunities to predict the onset of ENSO events in three oceans could have global socio-economic implications. Since ENSO is a global and natural part of the Earth's climate, it is important to know if the change in intensity and frequency could be the result of global warming. Low frequency changes have already been detected. Inter-decadal ENSO modulations may also exist.

El Niño and La Niña

The first signs of El Niño are as follows:

Rising air pressure over the Indian Ocean, Indonesia and Australia.
Drop in air pressure over Tahiti and the rest of the central and eastern Pacific Ocean.
The trade winds in the South Pacific are weakening or heading east.
Warm air appears next to Peru, causing rain in the deserts.
Warm water spreads from the western part of the Pacific Ocean to the east. She brings rain with her, causing it in areas where it is usually dry.

The warm El Niño Current, made up of plankton-poor tropical water and heated by its eastern branch in the Equatorial Current, replaces the cold, plankton-rich waters of the Humboldt Current, also known as the Peruvian Current, which contains large populations of game fish. Most years, warming lasts only a few weeks or months, after which weather patterns return to normal and fish catches increase. However, when El Niño conditions last several months, more extensive ocean warming occurs and its economic impact on local fisheries for the export market can be severe.

In the Pacific, La Niña is characterized by unusually cold temperatures in the eastern equatorial region compared to El Niño, which in turn is characterized by unusually high temperatures in the same region. Atlantic tropical cyclone activity generally increases during La Niña. The La Niña condition often occurs after El Niño, especially when the latter is very strong.

Southern Oscillation Index (SOI)

The Southern Oscillation Index is calculated from the monthly or seasonal fluctuations in the air pressure difference between Tahiti and Darwin.

Long-term negative SOI values often signal El Niño episodes. These negative values are usually associated with prolonged warming in the central and eastern tropical Pacific Ocean, a decrease in the strength of the Pacific trade winds and a decrease in precipitation in the east and north of Australia.

Extensive influence of El Niño conditions

As El Niño's warm waters feed the storms, it creates an increase in rainfall in the east-central and eastern Pacific Oceans.

In South America, the El Niño effect is more pronounced than in North America. El Niño is associated with warm and very wet summers (December-February) along the coasts of northern Peru and Ecuador, causing severe flooding whenever the event is strong. Effects during February, March, April can become critical. Southern Brazil and northern Argentina also experience wetter than normal conditions, but mostly during the spring and early summer. The central region of Chile gets a mild winter with plenty of rain, and the Peruvian-Bolivian Plateau experiences occasional winter snowfalls that are unusual for this region. Dryer and warmer weather is observed in the Amazon Basin, Colombia and Central America.

Warm Basin of the Western Hemisphere

A study of climate data has shown that there is an unusual warming of the Western Hemisphere Warm Basin in about half of the post-El Niño summers. This affects the weather in the region and seems to be related to the North Atlantic Oscillation.

Atlantic effect

Non-climatic effects

Along the east coast of South America, El Niño reduces the upwelling of cold, plankton-rich water that supports large populations of fish, which in turn support an abundance of seabirds whose droppings support the fertilizer industry.

It is postulated that El Niño led to the disappearance of the Mochico Indian tribe and other tribes of the pre-Columbian Peruvian culture.

Causes of El Niño

The mechanisms that can trigger El Niño events are still under investigation. It is difficult to find patterns that can show causes or allow predictions to be made.

History of the theory

The first mention of the term "El Niño" refers to the year when Captain Camilo Carrilo reported at the congress of the Geographical Society in Lima that Peruvian sailors called the warm north current "El Niño", since it is most noticeable in the Christmas area. However, even then, the phenomenon was only interesting because of its biological impact on the efficiency of the fertilizer industry.

For most of the twentieth century, El Niño was considered a large local phenomenon.

The history of the phenomenon

ENSO conditions have happened every 2-7 years for at least the last 300 years, but most have been mild.

Big ENSO events occurred in - , , - , , - , - and -1998.

The last El Niño events occurred in -, -,,,, 1997-1998 and -2003.

The 1997-1998 El Niño in particular was strong and brought international attention to the phenomenon, while it was unusual for the 1997-1998 period that El Niño was very frequent (but mostly weak).

El Niño in the history of civilization

Both civilizations were located in monsoonal regions, the moistening of which depends on the seasonal precipitation. However, at the indicated time, apparently, the rainy season was not able to provide the amount of moisture sufficient for the development of agriculture.

The ensuing drought and subsequent famine led to the decline of these civilizations, the researchers believe. They attribute climate change to the natural phenomenon El Niño, which refers to temperature fluctuations in the surface waters of the eastern Pacific Ocean in tropical latitudes. This leads to large-scale disturbances in atmospheric circulation, which causes droughts in traditionally wet regions and floods in dry ones.

Literature

Cesar N. Caviedes, 2001. El Nino in History: Storming Through the Ages(University Press of Florida)
Brian Fagan, 1999. Floods, Famines, and Emperors: El Niño and the Fate of Civilizations(Basic Books)
Michael H. Glantz, 2001. Currents of change, ISBN 0-521-78672-X
Mike Davis, Late Victorian Holocausts: El Niño Famines and the Making of the Third World(2001), ISBN 1-85984-739-0

Climate, Climatology

The first time I heard the word "El Niño" in the US was in 1998. At that time it a natural phenomenon was well known to Americans, but almost unknown in our country. And not surprising, because. El Niño originates in the Pacific Ocean off the coast of South America and greatly affects the weather in the southern states of the United States. El Niño(translated from Spanish El Nino- baby, boy) in the terminology of climatologists - one of the phases of the so-called Southern Oscillation, i.e. fluctuations in the temperature of the surface layer of water in the equatorial part of the Pacific Ocean, during which the area of heated surface waters shifts to the east. (For reference: the opposite phase of the oscillation - the displacement of surface waters to the west - is called La Niña (La Nina- baby, girl)). Periodically occurring in the ocean, the El Niño phenomenon strongly affects the climate of the entire planet. One of the largest El Niño occurred just in 1997-1998. It was so strong that it attracted the attention of the world community and the press. At the same time, theories about the connection of the Southern Oscillation with global climate changes spread. According to experts, the El Niño warming event is one of the main drivers of our natural climate variability.

In 2015 The World Meteorological Organization has reported that emerging ahead of time and dubbed "Bruce Lee" El Niño could be one of the most powerful since 1950. Its appearance was expected last year, based on data on the increase in air temperature, but these models did not justify themselves, and El Niño did not appear.

In early November, the American agency NOAA (National Oceanic and Atmospheric Administration) released a detailed report on the state of the Southern Oscillation and analyzed the possible development of El Niño in 2015-2016. The report is published on the NOAA website. The conclusions of this paper state that there are now all conditions for the formation of El Niño, average temperature surface of the equatorial Pacific Ocean (SST) has elevated values and continues to rise. The probability that El Niño will develop during the winter of 2015-2016 is 95% . A gradual decline in El Niño is predicted in the spring of 2016. The report has an interesting graph showing the change in SST since 1951. Blue areas represent lower temperatures (La Niña), and orange areas show higher temperatures (El Niño). The previous strong increase in SST by 2 °C was observed in 1998.

Data obtained in October 2015 suggest that the SST anomaly at the epicenter is already reaching 3°C.

Although the causes of El Niño are not yet fully understood, it is known that it begins with the trade winds weakening over several months. A series of waves move across the Pacific Ocean along the equator and create an array warm water near South America, where the ocean usually has low temperatures due to the rise of deep ocean waters to the surface. The weakening of the trade winds, with strong westerly winds counteracting them, could also create a twin cyclone (to the south and north of the equator), which is another sign of the future of El Niño.

Studying the causes of El Niño, geologists drew attention to the fact that the phenomenon occurs in the eastern part of the Pacific Ocean, where a powerful rift system has developed. The American researcher D. Walker found a clear connection between the increase in seismicity in the East Pacific Rise and El Niño. The Russian scientist G. Kochemasov saw another curious detail: the relief fields of oceanic warming almost one to one repeat the structure of the earth's core.

One of the interesting versions belongs to the Russian scientist - Doctor of Geological and Mineralogical Sciences Vladimir Syvorotkin. It was first mentioned back in 1998. According to the scientist, the most powerful centers of hydrogen-methane degassing are located in the hot spots of the ocean. And easier - sources of constant emission of gases from the bottom. Their visible signs are the outlets of thermal waters, black and white smokers. In the area of the coasts of Peru and Chile, during the years of El Niño, there is a massive release of hydrogen sulfide. Water boils, there is a terrible smell. At the same time, an amazing force is pumped into the atmosphere: approximately 450 million megawatts.

The El Niño phenomenon is now being studied and discussed more and more intensively. A team of researchers from the German National Center for Geosciences has concluded that the mysterious disappearance of the Mayan civilization in Central America could be caused by strong climate changes caused by El Niño. At the turn of the 9th and 10th centuries AD, at opposite ends of the earth, the two largest civilizations of that time almost simultaneously ceased to exist. We are talking about the Maya Indians and the fall of the Chinese Tang dynasty, followed by a period of internecine strife. Both civilizations were located in monsoonal regions, the moistening of which depends on the seasonal precipitation. However, there came a time when the rainy season was not able to provide enough moisture for the development of agriculture. The drought and subsequent famine led to the decline of these civilizations, the researchers believe. Scientists came to these conclusions by studying the nature of sedimentary deposits in China and Mesoamerica related to the indicated period. The last emperor of the Tang Dynasty died in 907 AD, and the last known Mayan calendar dates back to 903.

Climatologists and meteorologists say that El Niño2015, which will peak between November 2015 and January 2016, will be one of the strongest. El Niño will lead to large-scale disturbances in atmospheric circulation, which can cause droughts in traditionally wet regions and floods in dry ones.

A phenomenal phenomenon, which is considered one of the manifestations of the developing El Niño, is now observed in South America. The Atacama Desert, which is located in Chile and is one of the driest places on Earth, is covered with flowers.

This desert is rich in deposits of saltpeter, iodine, common salt and copper; no significant precipitation has been observed here for four centuries. The reason is that the Peruvian current cools the lower atmosphere and creates temperature inversion which prevents precipitation. Rain falls here once every few decades. However, in 2015, the Atacama was hit by unusually heavy rainfall. As a result, dormant bulbs and rhizomes (horizontally growing underground roots) sprouted. The pale plains of the Atacama were covered with yellow, red, purple and white flowers - nolans, bomareys, rhodophials, fuchsias and mallows. The desert bloomed for the first time in March, after unexpectedly intense rains caused floods in the Atacama and killed about 40 people. Now the plants have bloomed for the second time in a year, before the beginning of the southern summer.

What will El Niño 2015 bring? Expected that powerful ale Niño will bring long-awaited downpours to the drylands of the US. In other countries, the effect may be the opposite. In the Western Pacific, El Niño creates increased Atmosphere pressure, bringing dry and sunny weather to vast areas of Australia, Indonesia, and sometimes even India. El Niño's impact on Russia has so far been limited. It is believed that under the influence of El Niño in October 1997 in Western Siberia, the temperature was set above 20 degrees, and then they started talking about the retreat of the permafrost to the north. In August 2000, specialists from the Ministry of Emergency Situations explained precisely the impact El Niño phenomenon a series of hurricanes and downpours that swept across the country.

Where is El Niño located? Climate phenomena La Niña and El Niño and their impact on health and society. The natural phenomenon of El Niño

El Niño and La Niña

Southern Oscillation Index (SOI)

Extensive influence of El Niño conditions

Warm Basin of the Western Hemisphere

Atlantic effect

Non-climatic effects

Causes of El Niño

History of the theory

The history of the phenomenon

El Niño in the history of civilization

Links

Literature

El Niño and La Niña

Southern Oscillation Index (SOI)

Extensive influence of El Niño conditions

Warm Basin of the Western Hemisphere

Atlantic effect

Non-climatic effects

Causes of El Niño

History of the theory

The history of the phenomenon

El Niño in the history of civilization

Links

Literature