El Niño was replaced by La Niña: what does it mean. El Niño - the most powerful current in the world's oceans

Author: S. Gerasimov
On April 18, 1998, the Mir News newspaper published an article by N. Varfolomeeva “Moscow snowfall and the mystery of the El Niño phenomenon”, which stated: “... We have not yet learned to be scared at the word El Niño ... It is El Niño that is a threat to life on the planet ... The El Niño phenomenon is practically not studied, its nature is unclear, it cannot be predicted, which means that it is a time bomb in the full sense of the word ... If efforts are not immediately made to clarify the nature of this strange phenomenon, humanity cannot be sure of tomorrow ". Agree that all this looks quite ominous, it just becomes scary. Unfortunately, everything that is told in the newspaper is not fiction, not a cheap sensation to increase the circulation of the publication. El Niño is a real unpredictable natural phenomenon - a warm current, so affectionately named.
"El Niño" in Spanish means "baby", "little boy". Such a gentle name originated in Peru, where local fishermen have long faced an incomprehensible mystery of nature: in other years, the water in the ocean suddenly heats up and moves away from the coast. And it happens just before Christmas. That is why the Peruvians associated their miracle with the Christian sacrament of Christmas: in Spanish, El Niño is called the holy Christ Child. True, before it did not bring such troubles as now. Why, then, sometimes the phenomenon demonstrates its full force, while in other cases it hardly manifests itself? And what caused the Peruvian miracle, the consequences of which are very serious and sad?
For 20 years now, a whole scientific army has been exploring the space between Indonesia and South America. 13 meteorological ships, replacing each other, are constantly in these waters. Numerous buoys are equipped with instruments to measure water temperature from the surface to a depth of 400 meters. Seven aircraft and five satellites patrol the sky over the ocean to get a general picture of the state of the atmosphere, including understanding the mysterious natural phenomenon El Niño. This episodically emerging warm current off the coast of Peru and Ecuador is associated with the occurrence of adverse weather cataclysms around the world. It is difficult to follow it - this is not the Gulf Stream, stubbornly moving along the established route for millennia. And El Niño occurs like a jack-in-the-box every three to seven years. From the outside, it looks like this: from time to time in the Pacific Ocean - from the coast of Peru to the islands of Oceania - a very warm giant current appears, with a total area equal to that of the United States - about 100 million km2. It is stretched out with a long, tapering sleeve. Above this vast expanse, as a result of increased evaporation, colossal energy is pumped into the atmosphere. The El Niño effect releases 450 million megawatts of energy, which is equal to the total capacity of 300,000 large nuclear power plants. As if another - additional - the Sun rises from the Pacific Ocean, heating our planet! And then here, as if in a giant cauldron, between America and Asia, the special climatic dishes of the year are brewed.
Naturally, Peruvian fishermen are the first to celebrate his "birth". They are worried about the disappearance of schools of sardines off the coast. The immediate cause of the departure of the fish lies, as it turned out, in the disappearance of food. Sardines, and not only them, feed on phytoplankton, an integral part of which is microscopic algae. And algae need sunlight and nutrients, especially nitrogen and phosphorus. They are in ocean water, and their supply in the upper layer is constantly replenished by vertical currents going from the bottom to the surface. But when the El Niño current turns back towards South America, its warm waters "lock" the exit of deep waters. Nutrients do not rise to the surface, the reproduction of algae stops. The fish leave these places - it does not have enough food. But there are sharks. They also react to "malfunctions" in the ocean: bloodthirsty robbers are attracted by the temperature of the water - it rises by 5-9 ° C. It is in this sharp increase in the temperature of the surface layer of water in the eastern Pacific Ocean (in the tropical and central parts) that the phenomenon of El- Niño. What happens to the ocean?
In normal years, the warm surface waters of the ocean are transported and retained by easterly winds - the trade winds - in the western zone of the tropical Pacific Ocean, where the so-called tropical warm basin (TTB) is formed. It should be noted that the depth of this warm water layer reaches 100-200 meters. The formation of such a huge reservoir of heat is the main necessary condition for the birth of El Niño. At the same time, as a result of the surge, the ocean level off the coast of Indonesia is two feet higher than off the coast of South America. At the same time, the temperature of the water surface in the west in the tropical zone is on average + 29-30 ° С, and in the east + 22-24 ° С. trade winds. At the same time, the largest area of ​​heat and stationary unstable equilibrium in the ocean-atmosphere system (when all forces are balanced and the TTB is immobile) is formed above the TTB in the atmosphere.
For unknown reasons, once every three to seven years, the trade winds suddenly weaken, the balance is disturbed and the warm waters of the western basin rush to the east, creating one of the strongest warm currents in the oceans. Over a huge area in the eastern Pacific Ocean, in the tropical and central equatorial parts, there is a sharp increase in the temperature of the surface layer of the ocean. This is the onset of El Niño. Its beginning is marked by a long onslaught of heavy westerly winds. They replace the usual weak trade winds over the warm western part of the Pacific Ocean and block the rise of cold deep waters to the surface, that is, the normal circulation of water in the World Ocean is disrupted. Unfortunately, such a scientific, dry explanation of causes is nothing compared to the consequences.
But then a giant "baby" was born. Each of his "breath", each "wave of the hand" causes processes that are global in nature. El Niño is usually accompanied by environmental disasters: droughts, fires, heavy rains, causing flooding of vast areas of densely populated areas, which leads to the death of people and the destruction of livestock and crops in different parts of the Earth. El Niño has a significant impact on the state of the world economy. According to American experts, in 1982-1983, the economic damage from his "tricks" in the United States amounted to $13 billion and killed from one and a half to two thousand people, and according to the world's leading insurance company Munich Re, the damage in 1997-1998 is already estimated at 34 billion dollars and 24 thousand human lives.
Drought and rain, hurricanes, tornadoes and snowfalls are the main satellites of El Niño. All this, as if on command, falls together to the Earth. During his "coming" in 1997-1998, fires turned the rainforests of Indonesia to ashes, and then raged across the expanses of Australia. They reached the outskirts of Melbourne. Ashes flew to New Zealand - for 2000 kilometers. Tornadoes swept where they had never been. Sunny California was attacked by "Nora" - a tornado (as a tornado is called in the USA) of unprecedented size - 142 kilometers in diameter. He raced over Los Angeles, almost tearing the roofs off Hollywood film studios. Two weeks later, another tornado, the Paulina, hit Mexico. The famous resort of Acapulco was attacked by ten-meter ocean waves - buildings were destroyed, the streets were littered with debris, debris and beach furniture. The floods did not spare South America either. Hundreds of thousands of Peruvian peasants fled from the onset of water that fell from the sky, the fields were lost, flooded with mud. Where brooks used to murmur, stormy torrents swept through. The Chilean Atacama Desert, which has always been so unusually dry that NASA tested the Martian rover there, was hit by heavy rains. Catastrophic floods have also been observed in Africa.
In other parts of the planet, climate riots have also brought misfortune. On New Guinea - one of the largest islands on the planet - mainly in its eastern part, the earth is cracked from heat and drought. The tropical greenery dried up, the wells were left without water, the crops died. Half a thousand people died of starvation. There was a threat of a cholera epidemic.
Usually the “little boy” frolics for 18 months, so the season has time to change several times on the planet. It makes itself felt not only in summer, but also in winter. And if at the junction of 1982-1983 in the village of Paradise (USA) 28 m 57 cm of snow fell in a year, then in the winter season of 1998/99, due to the El Niño phenomenon at the ski base on Mount Baker, drifts of 29 meters increased in a few days 13 cm.
And if you think that these cataclysms do not affect the expanses of Europe, Siberia or the Far East, then you are deeply mistaken. Everything that happens in the Pacific Ocean reverberates throughout the planet. This is a monstrous snowfall in Moscow, and 11 floods of the Neva - a record for three hundred years of the existence of St. Petersburg, and + 20 ° C in October in Western Siberia. It was then that scientists began to talk with concern about the retreat of the permafrost boundary to the north.
And if earlier meteorologists and other specialists did not know what caused such a “collapse” in the weather, now the return movement of the El Niño current in the Pacific Ocean is considered the cause of all disasters. It is studied up and down, but cannot be squeezed into any framework. Scientists only shrug their hands - an anomalous climatic phenomenon.
And what is most interesting, paid attention to this phenomenon only in the last 100 years. But, as it turned out, the mysterious El Niño has existed for many millions of years. So, the archaeologist M. Moseli claims that 1100 years ago a powerful current, or rather natural disasters generated by it, destroyed the system of irrigation canals and thereby destroyed the highly developed culture of a large state in Peru. Mankind simply did not associate these natural disasters with it before. Scientists began to carefully analyze everything connected with the "baby", and even studied his "pedigree".
The Huon Peninsula near the island of New Guinea was chosen for the ajar veil of secrets of El Niño. It consists of a series of coral reef terraces. Part of this island is constantly rising due to tectonic movement, bringing to the surface samples of the coral reef, which are approximately 130,000 years old. Analysis of the isotopic and chemical data from these ancient corals has helped scientists identify 14 climatic "windows" of 20 to 100 years each. Cold (40,000 years ago) and warm periods (125,000 years ago) were analyzed in order to evaluate the characteristic features of the current in different climatic regimes. Coral samples obtained show that El Niño has not been as intense before as it has been in the last hundred years. Here are the years in which its anomalous activity was recorded: 1864,1871,1877-1878,1884,1891,1899,1911-1912, 1925-1926, 1939-1941, 1957-1958, 1965-1966, 1972, 1976, 1982 -1983, 1986-1987, 1992-1993, 1997-1998, 2002-2003. As you can see, the "phenomenon" of El Niño is happening more often, lasts longer and brings more and more trouble. The most intense periods are considered to be from 1982 to 1983 and from 1997 to 1998.
The discovery of the El Niño phenomenon is considered the event of the century. After extensive research, scientists have found that the warm western basin usually enters the opposite phase, the so-called La Niña, when the eastern Pacific cools 5°C below average, usually a year after El Niño. Then recovery processes begin to operate, which bring down cold fronts on the western North American coast, accompanied by hurricanes, tornadoes and thunderstorms. That is, the destructive forces continue their work. At the same time, it was noted that there were 18 La Niña phases for 13 El Niño periods. Scientists were only able to make sure that the distribution of TTB anomalies in the study area does not correspond to the normal one and therefore the empirical probability of the appearance of La Niña is 1.7 times greater than the probability of the appearance of El Niño.
The causes of occurrence and the increasing intensity of return currents are still a mystery to researchers. Climatologists in their research are often helped by historical materials. Australian scientist William de la Mare, after examining old whaling reports from 1931 to 1986 (when whaling was banned), determined that the hunt tended to end at the edge of the ice that formed. The figures show that the summer ice limit from the mid-1950s to the early 1970s shifted in latitude by 3°, that is, by about 1,000 kilometers to the south (we are talking about the Southern Hemisphere). This result coincides with the opinion of scientists who recognize the warming of the globe as a result of human activity. The German scientist M. Lateef from the Institute of Meteorology in Hamburg suggests that the perturbing influence of El Niño is increasing due to the growing greenhouse effect on Earth. Unpleasant news about rapid warming comes from the coast of Alaska: the glacier has become hundreds of meters thinner, salmon have changed spawning times, beetles that have multiplied from the heat are devouring the forest. Both polar caps of the planet cause alarm among scientists. However, representatives of science did not agree in their opinion in search of an answer to the global question: does the "greenhouse effect" in the Earth's atmosphere affect the intensity of El Niño?
But still, experts have learned to predict the arrival of a “baby”. And perhaps that is the only reason why the damage of the last two cycles did not have such tragic consequences. So a group of Russian scientists from the Obninsk Institute of Experimental Meteorology, led by V. Pudov, proposed a new approach to predicting El Niño. They decided to develop the already known idea that the occurrence of the current is associated with the development of tropical cyclones in the Philippine Sea region. Both typhoons and El Niño are consequences of the accumulation of excess heat in the surface layer of the ocean. The difference between these phenomena is in scale: typhoons release excess heat many times a year, and El Niño - once every few years. And it was also noticed that before El Niño forms, the ratio of atmospheric pressure always changes at two points: in Tahiti and in Darwin, Australia. Namely, this fluctuation in the ratio of pressures turned out to be the stable sign by which meteorologists can now know in advance about the approach of the "terrible baby."

edited news VENDETTA - 20-10-2010, 13:02

07.12.2007 14:23

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 and 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.

El Niño means "baby" in Spanish. This is the name given to the anomalous warming of the surface waters of the Pacific Ocean off the coast of Ecuador and Peru, which occurs every few years. This affectionate name reflects only 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 in a narrow seasonal range - 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 the tropical Pacific Ocean up to the 180th 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 easterly 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. An anomalous convection zone appears. 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 sets in the East 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 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 equatorial, eastern Africa, during June-August in the western United States and over central 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 over southeast Asia, over Primorye, Japan, the 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) occur along the southwest coast of the United States.

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 abnormalities around the world with the largest number of areas experiencing abnormally cool conditions. Cold winters in Japan and the Primorye, over South Alaska and western, central Canada. Cool summer seasons over southeast Africa, over India and southeast Asia. Warmer winters over the US Southwest.

Some aspects of telecommunication

Despite the fact that the main events associated with El Niño occur in the tropical zone, they are closely related to processes occurring in other regions of the globe. This can be traced on long-distance communications over the territory and in time - teleconnections. 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. The frequency of occurrence of cyclones and anticyclones in the northern part of the Pacific Ocean from 120°E was calculated at the Far Eastern Research Institute of Geological Research. up to 120°W It turned out that the cyclones in the band 40°-60° N.L. and anticyclones in the band 25°-40° N.L. formed in subsequent winters after El Niño more than in previous ones; processes in the winter months after El Niño are characterized by greater activity than before this period.

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. the summer depression over the Amur basin, as well as the winter Aleutian and Icelandic depressions, are more developed than usual.

On the territory of Russia during the El Niño years, areas of significant air temperature anomalies are distinguished. In spring, the temperature field is characterized by negative anomalies, that is, spring during El Niño years is usually cold in most of Russia. In summer, the center of below zero anomalies over the Far East and Eastern Siberia remains, while centers of above zero air temperature anomalies appear over Western Siberia and the European part of Russia. In the autumn months, significant air temperature anomalies over the territory of Russia were not identified. It should only be noted that in the European part of the country the temperature background is slightly lower than usual. El Niño years experience warm winters over most of the area. The center of negative anomalies can be traced only over the northeast of Eurasia.

We are currently in a weakening El Niño cycle - a period of average distribution of ocean surface temperatures. (The El Niño and La Niño events represent opposite extremes of ocean pressure and temperature cycles.)

Over the past few years, great progress has been made in the comprehensive study of the El Niño phenomenon. Scientists believe that the key issues of this problem are fluctuations in the system atmosphere - ocean - Earth. In this case, atmospheric oscillations are the so-called Southern Oscillation (coordinated surface pressure oscillations in a subtropical anticyclone in the southeast Pacific Ocean and in a trough stretching from northern Australia to Indonesia), ocean oscillations - El Niño and La Niño phenomena and Earth oscillations - movement of geographic poles. Also of great importance in the study of the El Niño phenomenon is the study of the impact of external cosmic factors on the Earth's atmosphere.

Especially for Primpogoda, the leading weather forecasters of the Department of Meteorological Forecasts of the Primorsky UGMS T. D. Mikhailenko and E. Yu. Leonova

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Presentation on the topic:

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slide number 2

Description of the slide:

El Niño is a fluctuation in the temperature of the surface layer of water in the equatorial part of the Pacific Ocean, which has a noticeable effect on the climate. In a narrower sense, El Niño is a phase of the Southern Oscillation in which the region of heated near-surface waters shifts to the east. At the same time, the trade winds weaken or stop altogether, upwelling slows down in the eastern part of the Pacific Ocean, off the coast of Peru. The opposite phase of the oscillation is called La Niña.

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The first signs of El Niño Increase in air pressure over the Indian Ocean, Indonesia and Australia. Drop in pressure over Tahiti, over the central and eastern parts of the Pacific Ocean. Weakening of the trade winds in the South Pacific until they stop and change the direction of the wind to the west. Warm air mass in Peru, rains in the Peruvian deserts. This is also the influence of El Niño

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Impact of El Niño on the climate of various regions In South America, the El Niño effect is most pronounced. Typically, this phenomenon causes warm and very humid summers (December to February) on the north coast of Peru and in Ecuador. If El Niño is strong, it causes severe flooding. Southern Brazil and northern Argentina also experience wetter than normal periods, but mostly in spring and early summer. Central Chile experiences a mild winter with plenty of rain, while Peru and Bolivia experience occasional winter snowfalls that are unusual for the region.

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Losses and losses More than 15 years ago, when El Niño first showed its character, meteorologists had not yet tied together the events of those years: droughts in India, fires in South Africa and hurricanes that swept through Hawaii and Tahiti. Later, when the causes of these violations in nature were clarified, the losses that the self-will of the elements brought were calculated. But it turned out that this is not all. For example, rains and floods are direct consequences of a natural disaster. But secondary ones also came after them - for example, mosquitoes multiplied in new swamps and brought a malaria epidemic to Colombia, Peru, India, Sri Lanka. In the state of Montana, bites of people by poisonous snakes have become more frequent. They approached the settlements, pursuing their prey - mice, and they left their settled places due to lack of water, they came closer to people and to water.

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From myths to reality Meteorologists' predictions have been confirmed: the catastrophic events associated with the course of El Niño, one after another, fall on the earth. Of course, it is very sad that all this is happening now. But still, it should be noted that for the first time humanity meets a global natural disaster, knowing its causes and the course of further development. The El Niño phenomenon is already fairly well understood. Science has solved the mystery that plagued Peruvian fishermen. They didn't understand why the ocean sometimes gets warmer around the Christmas period and the shoals of sardines off the coast of Peru disappear. Since the arrival of warm water coincided with Christmas, the current was named El Niño, which means "baby boy" in Spanish. The fishermen, of course, are interested in the immediate cause of the departure of the sardines...

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The fish are leaving... ...The fact is that sardines feed on phytoplankton. And algae need sunlight and nutrients - primarily nitrogen, phosphorus. They are in ocean water, and their supply in the upper layer is constantly replenished by vertical currents going from the bottom to the surface. But when the El Niño current turns back towards South America, its warm waters "lock" the exit of deep waters. Nutrients do not rise to the surface, the reproduction of algae stops. Fish leave these places - it does not have enough food.

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Magellan's mistake Magellan was the first European to swim across the planet's largest ocean. He named it "Quiet". As it turned out very soon, Magellan was mistaken. It is in this ocean that the most typhoons are born, it is he who produces three-quarters of the planet's clouds. Now we have also learned that the El Niño current that is born in the Pacific Ocean sometimes causes many different troubles and disasters on the planet...

slide number 9

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El Niño is an elongated tongue of highly heated water. It is equal in area to the United States. The heated water evaporates more intensively and “pumps” the atmosphere with energy faster. El Niño transfers 450 million megawatts to it, which is equivalent to the power of 300,000 large nuclear power plants. It is clear that this energy, according to the law of conservation of energy, does not disappear. And now in Indonesia, a catastrophe broke out in full force. First, there, on the island of Sumatra, a drought raged, then dried forests began to burn. In the impenetrable smoke that enveloped the entire island, the plane crashed upon landing, a tanker and a cargo ship collided in the sea. Smoke reached Singapore and Malaysia ..

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Description of the slide:

El Niño Years , 1986-1987, 1992-1993, 1997-1998. , in 1790-1793, 1828, 1876-1878, 1891, 1925-1926, 1982-1983 and 1997-1998 powerful El Niño phases were recorded, while, for example, in 1991-1992, 1993, 1994 this phenomenon, often repeated, it was weakly expressed. El Niño 1997-1998 was so strong that it attracted the attention of the world community and the press.

Fires and floods, droughts and hurricanes - all together hit our Earth at the end of the last century. 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 and floods did not spare South America either. The total damage from the willfulness of the elements amounted to about 50 billion dollars. Meteorologists consider the phenomenon to be the cause of all these disasters.

El Niño means "baby" in Spanish. This is the name given to the anomalous warming of the surface waters of the Pacific Ocean off the coast of Ecuador and Peru, which occurs every few years. This affectionate name reflects only 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 in a narrow seasonal range - 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 the tropical Pacific Ocean up to the 180th 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 easterly 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. An anomalous convection zone appears. Rains and hurricanes hit Central and South America. The La Niño phenomenon, the opposite of El Niño, manifests itself as a decrease in surface water temperature below the climatic norm in the east of the tropical Pacific Ocean. Unusually cold weather sets in the East 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, 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 observations, the reliability of the onset of El Niño or La Niño can be determined if:

1. At the equator, in the eastern 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 few decades 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 equatorial, eastern Africa, during June-August in the western United States and over central 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 over southeast Asia, over Primorye, Japan, the 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) occur along the southwest coast of the United States.

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 abnormalities around the world with the largest number of 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.

Some aspects of telecommunication

Despite the fact that the main events associated with El Niño occur in the tropical zone, they are closely related to processes occurring in other regions of the globe. This can be traced on long-distance communications over the territory and in time - teleconnections. 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. The frequency of occurrence of cyclones and anticyclones in the northern part of the Pacific Ocean from 120°E was calculated at the Far Eastern Research Institute of Geological Research. up to 120°W It turned out that the cyclones in the band 40°-60° N.L. and anticyclones in the band 25°-40° N.L. formed in subsequent winters after El Niño more than in previous ones; processes in the winter months after El Niño are characterized by greater activity than before this period.

During the El Niño years:

• weakened Honolulu and Asian anticyclones;
• the summer depression over southern Eurasia is filled, which is the main reason for the weakening of the monsoon over India;
• the summer depression over the Amur basin, as well as the winter Aleutian and Icelandic depressions, are more developed than usual.

On the territory of Russia during the El Niño years, areas of significant air temperature anomalies are distinguished. In spring, the temperature field is characterized by negative anomalies, that is, spring during El Niño years is usually cold in most of Russia. In summer, the center of below zero anomalies over the Far East and Eastern Siberia remains, while centers of above zero air temperature anomalies appear over Western Siberia and the European part of Russia. In the autumn months, significant air temperature anomalies over the territory of Russia were not identified. It should only be noted that in the European part of the country the temperature background is slightly lower than usual. El Niño years experience warm winters over much of the area. The center of negative anomalies can be traced only over the northeast of Eurasia.

We are currently in a period of weakening of the cycle - a period of average distribution of ocean surface temperatures. (The El Niño and La Niño events represent opposite extremes of ocean pressure and temperature cycles.)

Over the past few years, great progress has been made in the comprehensive study of the El Niño phenomenon. Scientists believe that the key issues of this problem are fluctuations in the system atmosphere - ocean - Earth. In this case, atmospheric fluctuations are the so-called Southern Oscillation (coordinated fluctuations in surface pressure in a subtropical anticyclone in the southeast Pacific Ocean and in a trough stretching from northern Australia to Indonesia), ocean fluctuations are El Niño and La Niño phenomena and fluctuations Earth - the movement of geographic poles. Also of great importance in the study of the El Niño phenomenon is the study of the impact of external cosmic factors on the Earth's atmosphere.

After a period of neutrality in the El Niño-La Niña cycle observed in mid-2011, the tropical Pacific began to cool in August, with a mild to moderate La Niña event observed from October to date.

“Forecasts made on the basis of mathematical models and their expert interpretation indicate that La Niña is close to maximum strength, and is likely to slowly begin to weaken in the coming months. However, existing methods do not allow predicting the situation beyond May, so it is not clear what the situation will be in the Pacific Ocean - whether it will be El Niño, La Niña or a neutral position, ”the message says.

Scientists note that the La Niña of 2011-2012 was much weaker than in 2010-2011. Models predict that temperatures in the Pacific will approach neutral values ​​between March and May 2012.

La Niña in 2010 was accompanied by a decrease in the area of ​​clouds and an increase in the trade winds. The decrease in pressure led to heavy rain in Australia, Indonesia and countries in Southeast Asia. In addition, according to meteorologists, it is La Niña that is responsible for heavy rains in southern and drought in eastern equatorial Africa, as well as for the arid situation in the central regions of southwestern Asia and South America.

El Niño (Spanish El Niño - Baby, Boy) or Southern Oscillation (English El Niño / La Niña - Southern Oscillation, ENSO) is a fluctuation in the temperature of the surface water layer in the equatorial Pacific Ocean, which has a noticeable effect on climate. In a narrower sense, El Niño is a phase of the Southern Oscillation in which the area of ​​heated near-surface waters shifts to the east. At the same time, the trade winds are weakening or even stopping altogether, and upwelling is slowing down in the eastern part of the Pacific Ocean, off the coast of Peru. The opposite phase of the oscillation is called La Niña (Spanish: La Niña - Baby, Girl). The characteristic time of oscillation is from 3 to 8 years, however, the strength and duration of El Niño in reality varies greatly. So, in 1790-1793, 1828, 1876-1878, 1891, 1925-1926, 1982-1983 and 1997-1998 powerful El Niño phases were recorded, while, for example, in 1991-1992, 1993, 1994 this phenomenon , often repeated, was weakly expressed. El Niño 1997-1998 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. Since the early 1980s, El Niño also occurred in 1986-1987 and 2002-2003.

Normal conditions along the western coast of Peru are determined by the cold Peruvian Current, which carries water from the south. Where the current turns west, along the equator, cold and plankton-rich water rises from deep depressions, which contributes to the active development of life in the ocean. The cold current itself determines the aridity of the climate in this part of Peru, forming deserts. The trade winds drive the heated surface layer of water to the western zone of the tropical Pacific Ocean, where the so-called tropical warm basin (TTB) is formed. In it, the water is heated to depths of 100-200 m. Atmospheric Walker circulation, manifested in the form of trade winds, coupled with low pressure over the Indonesia region, leads to the fact that in this place the level of the Pacific Ocean is 60 cm higher than in its eastern part . And the water temperature here reaches 29 - 30 ° C against 22 - 24 ° C off the coast of Peru. However, everything changes with the onset of El Niño. The trade winds are weakening, the TTB is spreading, and the temperature of the water is rising over a huge area of ​​the Pacific Ocean. In the region of Peru, the cold current is replaced by a warm water mass moving from the west to the coast of Peru, upwelling weakens, fish die without food, and westerly winds bring moist air masses to the desert, showers that even cause floods. The onset of El Niño reduces the activity of Atlantic tropical cyclones.

The first mention of the term "El Niño" dates back to 1892, when Captain Camilo Carrilo reported at the congress of the Geographical Society in Lima that Peruvian sailors called the warm north current "El Niño", as it is most noticeable during the days of the Catholic Christmas. In 1893, Charles Todd suggested that droughts in India and Australia occur at the same time. The same was pointed out in 1904 by Norman Lockyer. The connection of the warm northern current off the coast of Peru with floods in this country was reported in 1895 by Pezet and Eguiguren. The Southern Oscillation was first described in 1923 by Gilbert Thomas Walker. He introduced the terms Southern Oscillation, El Niño and La Niña, and considered the zonal convection circulation in the atmosphere in the equatorial zone of the Pacific Ocean, which now received his name. For a long time, almost no attention was paid to the phenomenon, considering it to be regional. Only towards the end of the 20th century. links El Niño with the planet's climate.

QUANTITATIVE DESCRIPTION

At present, for a quantitative description of the phenomenon, El Niño and La Niña are defined as temperature anomalies of the surface layer of the equatorial part of the Pacific Ocean with a duration of at least 5 months, expressed in a deviation of water temperature by 0.5 ° C to a greater (El Niño) or less (La Niña) side.

The first signs of El Niño:

Rising air pressure over the Indian Ocean, Indonesia and Australia.

The drop in pressure over Tahiti, over the central and eastern parts of the Pacific Ocean.

The weakening of the trade winds in the South Pacific until they stop and the wind direction changes to the west.
Warm air mass in Peru, rain in the Peruvian deserts.

In itself, a 0.5 °C increase in water temperature off the coast of Peru is considered only a condition for the occurrence of El Niño. Usually such an anomaly can exist for several weeks, and then safely disappear. And only a five-month anomaly, classified as an El Niño phenomenon, can cause significant damage to the region's economy due to a drop in fish catches.

The Southern Oscillation Index (SOI) is also used to describe El Niño. It is calculated as the difference in pressure over Tahiti and over Darwin (Australia). Negative values ​​of the index indicate the El Niño phase, while positive values ​​indicate La Niña.

IMPACT OF EL NIÑO ON THE CLIMATE OF DIFFERENT REGIONS

In South America, the El Niño effect is most pronounced. Typically, this phenomenon causes warm and very humid summers (December to February) on the north coast of Peru and in Ecuador. If El Niño is strong, it causes severe flooding. Such, for example, happened in January 2011. Southern Brazil and northern Argentina also experience wetter than usual periods, but mainly in spring and early summer. Central Chile experiences a mild winter with plenty of rain, while Peru and Bolivia experience occasional winter snowfalls that are unusual for the region. Dryer and warmer weather is observed in the Amazon, in Colombia and the countries of Central America. Humidity is dropping in Indonesia, increasing the chance of wildfires. This also applies to the Philippines and northern Australia. From June to August, dry weather occurs in Queensland, Victoria, New South Wales and eastern Tasmania. In Antarctica, the west of the Antarctic Peninsula, Ross Land, the Bellingshausen and Amundsen Seas are covered with large amounts of snow and ice. At the same time, the pressure increases and they become warmer. In North America, winters tend to get warmer in the Midwest and Canada. Wetter in central and southern California, northwestern Mexico and the southeastern United States, and drier in the Pacific Northwest. During La Niña, on the contrary, it becomes drier in the Midwest. El Niño also leads to a decrease in the activity of Atlantic hurricanes. Eastern Africa, including Kenya, Tanzania and the White Nile Basin, experience long rainy seasons from March to May. Droughts haunt the southern and central regions of Africa from December to February, mainly Zambia, Zimbabwe, Mozambique and Botswana.

An El Niño-like effect is sometimes observed in the Atlantic Ocean, where the water along the equatorial coast of Africa becomes warmer, while off the coast of Brazil it becomes colder. Moreover, there is a connection between this circulation and El Niño.

IMPACT OF EL NIÑO ON HEALTH AND SOCIETY

El Niño causes extreme weather patterns associated with epidemic disease frequency cycles. El Niño is associated with an increased risk of mosquito-borne diseases such as malaria, dengue fever and Rift Valley fever. Malaria cycles are associated with El Niño in India, Venezuela and Colombia. There has been an association with outbreaks of Australian encephalitis (Murray Valley Encephalitis - MVE) in southeast Australia after heavy rains and flooding caused by La Niña. A prime example is the severe El Niño outbreak of Rift Valley Fever following extreme rainfall in northeastern Kenya and southern Somalia in 1997-98.

It is also believed that El Niño may be associated with the cyclical nature of wars and the emergence of civil conflicts in countries whose climate depends on El Niño. A study of data from 1950 to 2004 showed that El Niño is associated with 21% of all civil conflicts of this period. At the same time, the risk of civil war in the years of El Niño is twice as high as in the years of La Niña. It is likely that the link between climate and military operations is mediated by crop failures, which often occur during hot years.

The La Niña climate phenomenon, associated with a decrease in water temperatures in the equatorial Pacific Ocean and affecting weather conditions almost throughout the globe, has disappeared and most likely will not return until the end of 2012, the World Meteorological Organization (WMO) said in a statement.

The La Nina phenomenon (La Nina, "girl" in Spanish) is characterized by an anomalous drop in water surface temperature in the central and eastern tropical Pacific. This process is the opposite of El Nino (El Nino, "boy"), which, on the contrary, is associated with warming in the same zone. These states replace each other with a frequency of about a year.

After a period of neutrality in the El Niño-La Niña cycle observed in mid-2011, the tropical Pacific began to cool in August, with a mild to moderate La Niña event observed from October to date. By early April, La Niña had completely disappeared, and so far, neutral conditions have been observed in the equatorial Pacific Ocean, experts write.

“(Analysis of simulation results) suggests that La Niña is unlikely to return this year, while the probabilities of remaining neutral and El Niño in the second half of the year are approximately equal,” the WMO said in a statement.

Both El Niño and La Niña affect the circulation patterns of ocean and atmospheric currents, which in turn affect weather and climate around the globe, causing droughts in some regions, hurricanes and heavy rains in others.

The climate phenomenon La Niña, which took place in 2011, was so strong that it eventually led to a drop in global sea levels by as much as 5 mm. La Niña shifted Pacific surface temperatures and changed precipitation patterns around the world as terrestrial moisture began to move out of the ocean and onto land as rain in Australia, northern South America, Southeast Asia .

The alternating dominance of a warm oceanic phase in the southern oscillation phenomenon, El Niño, or a cold phase, La Niña, can change world sea levels so dramatically, but satellite data inexorably indicate that somewhere since the 1990s, global levels water still rise to a height of about 3 mm.
As soon as El Niño comes, the rise in water levels begins to occur faster, but with a phase change almost every five years, a diametrically opposite phenomenon is observed. The strength of the effect of one or another phase also depends on other factors and clearly reflects the overall climate change towards its aggravation. Both phases of the southern oscillation are studied by many scientists around the world, as they contain many clues to what is happening on Earth and what awaits her.

The atmospheric La Niña event of moderate to strong intensity will last in the tropical Pacific until April 2011. This is stated in the information bulletin on El Niño/La Niña, released on Monday by the World Meteorological Organization.

As emphasized in the document, all model-based forecasts predict the continuation or possible strengthening of the La Niña phenomenon over the next 4-6 months, ITAR-TASS reports.

La Niña, which formed in June-July this year, replacing the El Niño event that ended in April, is characterized by unusually low water temperatures in the central and eastern equatorial Pacific Ocean. This disrupts the normal patterns of tropical precipitation and atmospheric circulation. El Niño is the exact opposite, characterized by unusually high water temperatures in the Pacific Ocean.

The effects of these phenomena can be felt in many parts of the planet, expressed in floods, storms, droughts, increases or, conversely, decreases in temperatures. La Niña typically results in heavy winter rainfall in the eastern equatorial Pacific, Indonesia, the Philippines, and severe droughts in Ecuador, northwestern Peru, and eastern equatorial Africa.
In addition, the phenomenon contributes to a decrease in global temperature, and this is most noticeable from December to February in northeast Africa, in Japan, in southern Alaska, in central and western parts of Canada, in southeast Brazil.

The World Meteorological Organization /WMO/ today in Geneva said that in August this year, the La Niña climate phenomenon was again noted in the equatorial region of the Pacific Ocean, which can increase in intensity and continue until the end of this year or the beginning of next year.

The latest WMO report on El Niño and La Niña states that the current La Niña event will peak at the end of this year, but will be less intense than it was in the second half of 2010. Due to its uncertainty, WMO invites the countries of the Pacific Ocean basin to closely monitor its development and promptly report possible droughts and floods due to it.

The La Niña phenomenon implies the phenomenon of an anomalous prolonged large-scale cooling of water in the eastern and central parts of the Pacific Ocean near the equator, which gives rise to a global climate anomaly. The previous La Niña event led to a spring drought on the West Pacific coast, including China.