What is the name of the sport from El Niño? El Niño - what is it? Where the current is formed, its direction
The circulation named after Volcker is a significant aspect of the Pacific phenomenon ENSO (El Nino Southern Oscillation). ENSO is many 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 warm events, El Niño warms up and expands across much of the Pacific tropics and becomes directly correlated with SOI (Southern Oscillation Index) intensity. While ENSO events occur primarily between the Pacific and Indian Oceans, ENSO events in the Atlantic Ocean lag behind the former by 12 to 18 months. Most of the countries that experience ENSO events are developing ones, with economies that are heavily dependent on the agricultural and fishing sectors. New capabilities to predict the onset of ENSO events in three oceans could have global socioeconomic implications. Since ENSO is a global and natural part of the Earth's climate, it is important to know whether changes in intensity and frequency could be a result of global warming. Low frequency changes have already been detected. Interdecadal ENSO modulations may also exist.
El Niño and La Niña
Common Pacific pattern. Equatorial winds collect a warm pool of water to the west. Cold waters rise to the surface along the South American coast.AND La Niña officially defined as long-lasting marine surface temperature anomalies greater than 0.5 °C crossing the central tropical Pacific Ocean. When a condition of +0.5 °C (-0.5 °C) is observed for a period of up to five months, it is classified as an El Niño (La Niña) condition. If the anomaly persists for five months or longer, 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.
Increase in air pressure over the Indian Ocean, Indonesia and Australia.
A drop in air pressure over Tahiti and the rest of the central and eastern Pacific Ocean.
Trade winds in the South Pacific are weakening or heading east.
Warm air appears near Peru, causing rain in the deserts.
Warm water spreads from the western part of the Pacific Ocean to the eastern. It brings rain with it, causing it to occur in areas that are usually dry.
Warm El Niño current, consisting of plankton-depleted tropical water and warmed by its eastern channel 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, the 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 for several months, more extensive ocean warming occurs and its economic impact on local fisheries for the external market can be severe.
The Volcker circulation is visible on the surface as easterly trade winds, which move water and air heated by the sun westward. It also creates oceanic upwelling off the coasts of Peru and Ecuador, bringing cold plankton-rich waters to the surface, increasing fish populations. The western equatorial Pacific Ocean is characterized by warm, humid weather and low atmospheric pressure. The accumulated moisture falls 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 Ocean, La Niña is characterized by unusually cold temperatures in the eastern equatorial region compared to El Niño, which in turn is characterized by unusually warm temperatures in the same region. Atlantic tropical cyclone activity generally increases during La Niña. A La Niña condition often occurs after an El Niño, especially when the latter is very strong.
Southern Oscillation Index (SOI)
The Southern Oscillation Index is calculated from monthly or seasonal fluctuations in the air pressure difference between Tahiti and Darwin.Long-lasting negative SOI values often signal El Niño episodes. These negative values typically accompany continued warming of the central and eastern tropical Pacific, decreased strength of the Pacific trade winds, and decreased rainfall in eastern and northern Australia.
Positive values SOIs are associated with strong Pacific trade winds and warming water temperatures in northern Australia, well known as a La Niña episode. The waters of the central and eastern tropical Pacific Ocean become colder during this time. Together this increases the likelihood of more rainfall than normal in eastern and northern Australia.
El Niño influence
As El Niño's warm waters fuel storms, it creates increased precipitation in the east-central and eastern Pacific Ocean.In South America, the El Niño effect is more pronounced than in North America. El Niño is associated with warm and very wet summer periods (December-February) along the coast of northern Peru and Ecuador, causing severe flooding whenever the event is severe. The effects during February, March, April may become critical. Southern Brazil and northern Argentina also experience wetter than normal conditions, but mainly during the spring and early summer. The central region of Chile gets a mild winter with a large number rains, and the Peruvian-Bolivian Plateau sometimes experiences winter snowfalls that are unusual for this region. Drier and warm weather observed in the Amazon Basin, Colombia and Central America.
Direct effects of El Niño lead to decreased humidity in Indonesia, increasing the likelihood of forest fires, 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 western Antarctic Peninsula, Ross Land, Bellingshausen and Amundsen seas are covered with large amounts of snow and ice during El Niño. The latter two and the Wedell Sea become warmer and are under higher atmospheric pressure.
In North America, winters are generally warmer than normal in the Midwest and Canada, while central and southern California, northwestern Mexico and the southeastern United States are getting wetter. The Pacific Northwest states, in other words, dry out during El Niño. Conversely, during La Niña, the US Midwest dries out. El Niño is also associated with decreased hurricane activity in the Atlantic.
East Africa, including Kenya, Tanzania and the White Nile Basin, experience long periods of rain from March to May. Droughts plague southern and central Africa from December to February, mainly Zambia, Zimbabwe, Mozambique and Botswana.
Warm Pool of the Western Hemisphere. A study of climate data showed that approximately half of the post-El Niño summers experienced unusual warming in the Western Hemisphere Warm Pool. This influences the weather in the region and appears to have a connection to the North Atlantic Oscillation.
Atlantic effect. An El Niño-like effect is sometimes observed in the Atlantic Ocean, where water along the equatorial African coast becomes warmer and water off the coast of Brazil becomes colder. This can be attributed to the Volcker circulation over South America.
Non-climatic effects of El Niño
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 abundant seabirds, whose droppings support the fertilizer industry.Local fishing industries along coastlines may experience shortages of fish during prolonged El Niño events. The world's largest fisheries collapse due to overfishing, which occurred in 1972 during El Niño, led to a decline in the Peruvian anchovy population. During the events of 1982-83, populations of southern horse mackerel and anchovies declined. Although the number of shells in warm water increased, hake went deeper into cold water, and shrimp and sardines went south. But the catch of some other fish species was increased, for example, the common horse mackerel increased its population during warm events.
Changing locations and types of fish due to changing conditions have presented challenges for the fishing industry. The Peruvian sardine has moved towards the Chilean coast due to El Niño. Other conditions have only led to further complications, such as the Chilean government creating fishing restrictions in 1991.
It is postulated that El Niño led to the extinction of the Indian Mochico tribe and other tribes of the pre-Columbian Peruvian culture.
Causes that give rise to El Niño
The mechanisms that may cause El Niño events are still being researched. It is difficult to find patterns that can show causes or allow predictions to be made.Bjerknes suggested in 1969 that abnormal warming in the eastern Pacific Ocean could be attenuated by east-west temperature differences, causing weakening in the Volcker circulation and trade winds that move warm water westward. The result is an increase in warm water to the east.
Virtky in 1975 suggested that the trade winds could create a westerly bulge of warm waters, and any weakening of the winds could allow warm waters to move east. However, no bulges were noticed on the eve of the events of 1982-83.
Rechargeable Oscillator: Some mechanisms have been proposed that when warm areas are created in the equatorial region, they are dissipated to higher latitudes through El Niño events. The cooled areas are then recharged with heat for several years before the next event occurs.
Western Pacific Oscillator: In the western Pacific Ocean, several weather conditions could cause easterly wind anomalies. For example, a cyclone in the north and an anticyclone in the south result in an easterly wind between them. Such patterns can interact with the westerly flow across the Pacific Ocean and create a tendency for the flow to continue eastward. A weakening of the westerly current at this time may be the final trigger.
The equatorial Pacific Ocean can lead to El Niño-like conditions with a few random variations in behavior. External weather patterns or volcanic activity can be such factors.
The Madden-Julian Oscillation (MJO) is a critical source of variability that may contribute to the sharper evolution leading to El Niño conditions through fluctuations in low-level winds and precipitation over the western and central regions. Pacific Ocean. The eastward propagation of oceanic Kelvin waves may be caused by MJO activity.
History of El Niño
The first mention of the term "El Niño" dates back to 1892, when Captain Camilo Carrilo reported at a congress Geographical Society in Lima that Peruvian sailors called the warm northerly current "El Niño" because it is most noticeable around Christmas. However, even then the phenomenon was interesting only because of its biological impact on the efficiency of the fertilizer industry.Normal conditions along the western Peruvian coast are cold south current(Peruvian Current) with water upwelling; plankton upwelling 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 land. The connection with flooding was reported in 1895 by Pezet and Eguiguren.
Towards the end of the nineteenth century there was increased interest in predicting climate anomalies (for food production) in India and Australia. Charles Todd suggested in 1893 that droughts in India and Australia occur at the same time. Norman Lockyer pointed out the same thing in 1904. In 1924, Gilbert Volcker first coined the term "Southern Oscillation."
For most of the twentieth century, El Niño was considered a large local phenomenon.
The Great El Niño of 1982-83 led to a sharp rise in the interest of the scientific community in this phenomenon.
History of the phenomenon
ENSO conditions have occurred every 2 to 7 years for at least the last 300 years, but most of them have been weak.
Major ENSO events occurred in 1790–93, 1828, 1876–78, 1891, 1925–26, 1982–83, and 1997–98.
Latest events El Niño occurred in 1986-1987, 1991-1992, 1993, 1994, 1997-1998 and 2002-2003.
The 1997–1998 El Niño in particular was strong and brought international attention to the phenomenon, while what was unusual about the 1990–1994 period was that El Niño occurred very frequently (but mostly weakly).
El Niño in the history of civilization
The mysterious disappearance of the Mayan civilization in Central America could be caused by severe climate changes. This conclusion was reached by a group of researchers from the German National Center for Geosciences, writes the British newspaper The Times.Scientists tried to establish why, at the turn of the 9th and 10th centuries AD, at opposite ends of the earth, the two largest civilizations of that time ceased to exist almost simultaneously. We are talking about the Mayan Indians and the fall of the Chinese Tang Dynasty, which was followed by a period of internecine strife.
Both civilizations were in monsoon regions, the moisture of which depends on seasonal precipitation. However, at this time, apparently, the rainy season was not able to provide the amount of moisture sufficient for the development agriculture.
The ensuing drought and subsequent famine led to the decline of these civilizations, researchers believe. They associate climate change with the natural phenomenon "El Niño", which means temperature fluctuations surface waters of the eastern part Pacific Ocean in tropical latitudes. This leads to large-scale disturbances in atmospheric circulation, causing droughts in traditionally wet regions and floods in dry ones.
Scientists came to these conclusions by studying the nature of sedimentary deposits in China and Mesoamerica dating back to this period. The last emperor of the Tang Dynasty died in 907 AD, and the last known Mayan calendar dates back to 903.
In the World Ocean, special phenomena (processes) are observed that can be considered 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, a distinction must be made between the El Niño current and the El Niño phenomenon.
El Niño current - a constant current, small on an oceanic scale, off the northwestern coast of South America. It can be traced from the Gulf of Panama 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 Peru-Chile Current and coastal upwelling into the open ocean. Ocean surface temperatures in the coastal zone of Ecuador and Peru rise to 21–23 0 C, and sometimes up to 25–29 0 C. The anomalous development of this warm current, which lasts almost six months - from December to May and which usually appears around Catholic Christmas, is called "El Niño" - from the Spanish "El Nico - the baby (Christ)." It was first noticed in 1726.
This purely oceanological process has tangible and often catastrophic environmental consequences on land. Due to the sharp warming of water in the coastal zone (by 8-14 0 C), the amount of oxygen and, accordingly, the biomass of cold-loving species of phyto- and zooplankton, the main food of anchovies and other commercial fish of the Peruvian region, significantly decreases. A huge number of fish either die or disappear from this water area. Peruvian anchovy catches fall 10 times in such years. After the fish, the birds that feed on them also disappear. As a result of this natural disaster, South American fishermen are going bankrupt. In previous years, the abnormal development of El Niño led to famine in several countries on the Pacific coast of South America. . In addition, during the passage of El Niño deteriorate sharply weather conditions 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 for the increasing frequency of weather anomalies 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 Pacific Ocean, which causes intense turbulent heat and moisture exchange between the ocean and the atmosphere.
Currently, the term "El Niño" is used to refer 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, warm surface ocean waters are held by easterly winds - trade winds - in the western zone of the tropical Pacific Ocean, where the so-called tropical warm pool (TTB) is formed. The depth of this warm layer of water reaches 100-200 meters, and it is the formation of such a large heat reservoir that is the main and necessary condition for the transition to the El Niño phenomenon. At this time, the water surface temperature in the west of the ocean in the tropical zone is 29-30°, while in the east it is 22-24°C. This difference in temperature is explained by the rise of cold deep waters to the ocean surface off the west coast of South America. At the same time, in the equatorial part of the Pacific Ocean, a water area with a huge reserve of heat is formed and equilibrium is observed in the ocean-atmosphere system. This is a situation of normal balance.
Approximately once every 3-7 years, the balance is disrupted, and the warm waters of the western Pacific Ocean move eastward, and over a huge area of water in the equatorial eastern part of the ocean there is a sharp increase in the temperature of the surface layer of water. The El Niño phase begins, the beginning of which is marked by sudden heavy westerly winds (Fig. 22). They reverse the usual weak trade winds over the warm western Pacific and prevent cold, deep waters off the west coast of South America from rising to the surface. Related El Niño atmospheric phenomena 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, 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 of heavy rainfall shifts from the western to the eastern Pacific Ocean. Rain and hurricanes hit Central and South America.
Rice. 22. Normal conditions and the onset phase 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 La Niña phenomenon (in Spanish La Niça - “girl”) - the “antipode” of El Niño is somewhat different. The La Niña phenomenon manifests itself as a decrease in surface water temperature below the climate norm in the eastern equatorial zone of the Pacific Ocean. Installation here is unusual cold weather. During the formation of La Niña, easterly winds from the west coast of the Americas increase significantly. Winds shift the warm water zone (WWZ), and the “tongue” of cold waters stretches for 5000 kilometers in exactly the place (Ecuador - Samoa Islands) where during El Niño there should be a belt of warm waters. This belt of warm waters moves to the western Pacific Ocean, causing powerful monsoon rains in Indochina, India and Australia. At the same time, the countries of the Caribbean and the United States suffer from droughts, dry winds and tornadoes.
La Niña cycles occurred in 1984-85, 1988-89 and 1995-96.
Although the atmospheric processes developing 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 storms than during El Niño.
The occurrence of El Niño or La Niña can be predicted if:
1. Near the equator in the eastern part of the Pacific Ocean, an area of warmer water than usual (El Niño phenomenon) or colder water (La Niña phenomenon) forms.
2. The atmospheric pressure trend between the port of Darwin (Australia) and the island of Tahiti (Pacific Ocean) is compared. During El Niño, pressure will be low in Tahiti and high in Darwin. During La Niña it is the other way around.
Research has established 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 represent large-scale changes in ocean temperature, precipitation, atmospheric circulation, and vertical air movements over the tropical Pacific Ocean and lead to abnormal weather conditions around the globe.
During El Niño years in the tropics, precipitation increases over areas east of the central Pacific Ocean and decreases over northern Australia, Indonesia and the Philippines. In December-February, above-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 is also responsible for large-scale air temperature anomalies around the world.
During El Niño years, energy transfer into 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 El Niño years:
1. The Honolulu and Asian anticyclones are weakened;
2. The summer depression over southern Eurasia is filled, which is the main reason for the weakening of the monsoon over India;
3. The winter Aleutian and Icelandic lows are more developed than usual.
During La Niña years, precipitation increases over the western equatorial Pacific Ocean, Indonesia, and the Philippines and is almost completely absent in the eastern part of the ocean. More precipitation falls in northern South America, South Africa and southeastern Australia. Drier than normal conditions are observed along the coast of Ecuador, northwestern Peru and equatorial eastern Africa. There are large-scale temperature excursions around the world, with the largest number of areas experiencing abnormally cool conditions.
Over the past decade, great strides have 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 connection 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 trade wind system and monsoon winds and, accordingly, surface ocean currents.
The El Niño phenomenon is increasingly affecting the global economy. So, this phenomenon of 1982-83. provoked terrible rainfalls in the countries of South America, caused enormous losses, and the economies of many countries were paralyzed. The effects of El Niño were felt by half of the world's population.
The strongest El Niño of 1997-1998 was the strongest during the entire observation period. It caused the most powerful hurricane in the history of meteorological observations, sweeping 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 rains generally occur once every ten years, a huge lake with an area of tens of square kilometers has formed. Unusually warm weather was recorded in South Africa, southern Mozambique, Madagascar, and unprecedented drought reigned in Indonesia and the Philippines, leading to forest fires. India experienced virtually no normal monsoon rains, while arid Somalia received significantly above normal rainfall. The total damage from the disaster amounted to about 50 billion dollars.
El Niño 1997-1998 significantly affected the average global air temperature of the Earth: it exceeded normal by 0.44°C. In the same year, 1998, the highest average annual air temperature was recorded on Earth for all years of instrumental observations.
The collected data indicate the regular occurrence of El Niño with an interval ranging from 4 to 12 years. The duration of El Niño itself varies from 6–8 months to 3 years, most often it is 1–1.5 years. This great variability makes it difficult to predict the phenomenon.
The influence of the climatic phenomena El Niño and La Niña, and therefore the number of unfavorable weather conditions on the planet, according to climate specialists, will increase. Therefore, humanity must closely monitor and study these climate phenomena.
The natural phenomenon El Niño, which took place in 1997-1998, had no equal in scale in the entire history of observations. What is this mysterious phenomenon that has caused so much noise and attracted close attention from the media?
In scientific terms, El Niño is a complex of interdependent changes in thermobaric and chemical parameters of the ocean and atmosphere, taking on the character natural disasters. According to reference literature, it is warm current, which sometimes occurs for unknown reasons off the coast of Ecuador, Peru and Chile. Translated from Spanish, "El Niño" means "baby". Peruvian fishermen gave it this name because warming waters and associated mass fish kills usually occur at the end of December and coincide with Christmas. Our magazine already wrote about this phenomenon in No. 1 in 1993, but since that time researchers have accumulated a lot of new information.
NORMAL SITUATION
To understand the anomalous nature of the phenomenon, let us first consider the usual (standard) climate situation off the South American coast of the Pacific Ocean. It is quite peculiar and is determined by the Peruvian Current, which carries cold waters from Antarctica along the western coast of South America to the Galapagos Islands lying on the equator. Usually the trade winds blowing here from the Atlantic, crossing the high-mountain barrier of the Andes, leave moisture on their eastern slopes. And therefore the western coast of South America is a dry rocky desert, where rain is extremely rare - sometimes it does not fall for years. When the trade winds collect so much moisture that they carry it to the western shores of the Pacific Ocean, they form here the predominant westerly direction of surface currents, causing a surge of water off the coast. It is unloaded by the counter-trade Cromwell Current in the equatorial zone of the Pacific Ocean, which covers a 400-kilometer strip here and at depths of 50-300 m transports huge masses of water back to the east.
The attention of specialists is attracted by the colossal biological productivity of coastal Peruvian-Chilean waters. Here, in a small space, constituting a fraction of a percent of the entire water area of the World Ocean, the annual production of fish (mainly anchovy) exceeds 20% of the global total. Its abundance attracts huge flocks of fish-eating birds - cormorants, gannets, pelicans. And in areas where they accumulate, colossal masses of guano (bird droppings) - a valuable nitrogen-phosphorus fertilizer - are concentrated; its deposits, ranging in thickness from 50 to 100 m, became the object of industrial development and export.
CATASTROPHE
During El Niño years, the situation changes dramatically. First, the water temperature rises by several degrees and mass death or departure of fish from this water area begins, and as a result, birds disappear. Then the eastern Pacific falls atmospheric pressure, clouds appear above it, the trade winds subside, and air currents over the entire equatorial zone of the ocean change direction. Now they are moving from west to east, carrying moisture from the Pacific region and dumping it on the Peruvian-Chilean coast.
Events are developing especially catastrophically at the foot of the Andes, which now block the path of the western winds and receive all their moisture onto their slopes. As a result, floods, mudflows, and floods are raging in a narrow strip of rocky coastal deserts on the western coast (at the same time, the territories of the Western Pacific region are suffering from terrible drought: they are burning tropical forests in Indonesia, New Guinea, crop yields in Australia are falling sharply). To top it all off, so-called “red tides” are developing from the Chilean coast to California, caused by the rapid growth of microscopic algae.
So, the chain of catastrophic events begins with a noticeable warming of surface waters in the eastern Pacific Ocean, which has recently been successfully used to predict El Niño. A network of buoy stations has been installed in this water area; with their help, the temperature of ocean water is constantly measured, and the data obtained is promptly transmitted via satellites to research centers. As a result, it was possible to warn in advance about the onset of the most powerful El Niño known to date - in 1997-98.
At the same time, the reason for the heating of ocean water, and therefore the occurrence of El Niño itself, is still not completely clear. Oceanographers explain the appearance of warm water south of the equator by a change in the direction of the prevailing winds, while meteorologists consider the change in winds to be a consequence of heating the water. Thus, a kind of vicious circle is created.
To get closer to understanding the genesis of El Niño, let us pay attention to a number of circumstances that are usually overlooked by climate specialists.
EL NINO DEGASION SCENARIO
For geologists, the following fact is absolutely obvious: El Niño develops over one of the most geologically active areas of the world rift system - the East Pacific Rise, where the maximum spreading rate (spreading of the ocean floor) reaches 12-15 cm/year. In the axial zone of this underwater ridge, a very high heat flow from the earth’s interior is noted, manifestations of modern basaltic volcanism are known here, thermal water outlets and traces of the intensive process of modern ore formation in the form of numerous black and white “smokers” were discovered.
In the water area between 20 and 35 south. w. Nine hydrogen jets were recorded at the bottom - the release of this gas from the bowels of the earth. In 1994, an international expedition discovered the world's most powerful hydrothermal system here. In its gas emanations, the isotope ratios 3 He/4 He turned out to be abnormally high, which means: the source of degassing is located at great depth.
A similar situation is typical for other “hot spots” on the planet - Iceland, Hawaiian Islands, Red Sea. There, at the bottom there are powerful centers of hydrogen-methane degassing and above them, most often in the Northern Hemisphere, the ozone layer is destroyed
, which gives grounds to apply the model I created for the destruction of the ozone layer by hydrogen and methane flows to El Niño.
This is roughly how this process begins and develops. Hydrogen, released from the ocean floor from the rift valley of the East Pacific Rise (its sources were instrumentally discovered there) and reaching the surface, reacts with oxygen. As a result, heat is generated, which begins to warm up the water. The conditions here are very favorable for oxidative reactions: the surface layer of water is enriched with oxygen during wave interaction with the atmosphere.
However, the question arises: can hydrogen coming from the bottom reach the ocean surface in noticeable quantities? A positive answer was given by the results of American researchers who discovered twice the content of this gas in the air over the Gulf of California, compared to the background level. But here at the bottom there are hydrogen-methane sources with a total flow rate of 1.6 x 10 8 m 3 /year.
Hydrogen, rising from the depths of water into the stratosphere, forms an ozone hole into which ultraviolet and infrared light “falls.” solar radiation. Falling onto the surface of the ocean, it intensifies the heating of its upper layer that has begun (due to the oxidation of hydrogen). Most likely, it is the additional energy of the Sun that is the main and determining factor in this process. The role of oxidative reactions in heating is more problematic. This could not be discussed if it were not for the significant (from 36 to 32.7% o) desalination of ocean water that occurs synchronously with it. The latter is probably accomplished by the very addition of water that is formed during the oxidation of hydrogen.
Due to the heating of the surface layer of the ocean, the solubility of CO 2 in it decreases, and it is released into the atmosphere. For example, during the El Niño of 1982-83. An additional 6 billion tons of carbon dioxide entered the air. Water evaporation also increases, and clouds appear over the eastern Pacific Ocean. Both water vapor and CO 2 are greenhouse gases; they absorb thermal radiation and become an excellent accumulator of additional energy coming through the ozone hole.
Gradually the process is gaining momentum. Anomalous heating of the air leads to a decrease in pressure, and a cyclonic region forms over the eastern part of the Pacific Ocean. It is this that breaks the standard trade wind pattern of atmospheric dynamics in the area and “sucks” air from the western part of the Pacific Ocean. Following the subsidence of the trade winds, the surge of water off the Peruvian-Chilean coast decreases and the equatorial Cromwell countercurrent ceases to operate. Strong heating of the water leads to the formation of typhoons, which is very rare in normal years (due to the cooling influence of the Peruvian Current). From 1980 to 1989, ten typhoons occurred here, seven of them in 1982-83, when El Niño raged.
BIOLOGICAL PRODUCTIVITY
Why is biological productivity so high off the west coast of South America? According to experts, it is the same as in the abundantly “fertilized” fish ponds of Asia, and 50 thousand times higher (!) than in other parts of the Pacific Ocean, if calculated by the number of fish caught. Traditionally, this phenomenon is explained by upwelling - a wind-driven movement of warm water from the shore, forcing cold water enriched with nutritional components, mainly nitrogen and phosphorus, to rise from the depths. During El Niño years, when the wind changes direction, upwelling is interrupted, and therefore, nutrient water stops flowing. As a result, fish and birds die or migrate due to starvation.
All this resembles a perpetual motion machine: the abundance of life in surface waters is explained by the supply of nutrients from below, and their excess below is explained by the abundance of life above, because dying organic matter settles to the bottom. However, what is primary here, what gives impetus to such a cycle? Why does it not dry up, although, judging by the power of the guano deposits, it has been active for millennia?
The mechanism of wind upwelling itself is not very clear. The associated rise of deep water is usually determined by measuring its temperature on profiles of different levels oriented perpendicular to the coastline. Isotherms are then constructed that show the same low temperatures near the coast and at great depths away from it. And in the end they conclude that cold waters are rising. But it is known: the low temperature near the coast is caused by the Peruvian Current, so the described method for determining the rise of deep waters is hardly correct. Finally, another ambiguity: the profiles mentioned are built across the coastline, and the prevailing winds here blow along it.
I am by no means going to overthrow the concept of wind upwelling - it is based on an understandable physical phenomenon and has a right to life. However, upon closer acquaintance with it in this area of the ocean, all of the listed problems inevitably arise. Therefore, I propose another explanation for the anomalous biological productivity off the western coast of South America: it is again determined by the degassing of the earth's interior.
In fact, not the entire Peruvian-Chilean coastal strip is equally productive, as it should be under the influence of climatic upwelling. There are two separate “spots” here - northern and southern, and their position is controlled by tectonic factors. The first is located above a powerful fault extending from the ocean to the continent south of the Mendana fault (6-8 o S) and parallel to it. The second spot, somewhat smaller in size, is located just north of the Nazca Ridge (13-14 S latitude). All of these oblique (diagonal) geological structures running from the East Pacific Rise towards South America are essentially degassing zones; along them, a huge number of different chemical compounds. Among them there are, of course, vital elements - nitrogen, phosphorus, manganese, and plenty of microelements. In the thickness of the coastal Peruvian-Ecuadorian waters, the oxygen content is the lowest in the entire World Ocean, since the main volume here is made up of reduced gases - methane, hydrogen sulfide, hydrogen, ammonia. But the thin surface layer (20-30 m) is abnormally rich in oxygen due to the low temperature of the water brought here from Antarctica by the Peruvian Current. In this layer above fault zones - sources of endogenous nutrients - unique conditions for the development of life are created.
However, there is an area in the World Ocean that is not inferior in bioproductivity to the Peruvian one, and perhaps even superior to it - off the western coast of South Africa. It is also considered a wind upwelling zone. But the position of the most productive area here (Walvis Bay) is again controlled by tectonic factors: it is located above a powerful fault zone running from the Atlantic Ocean to the African continent somewhat north of the South Tropic. And the cold, oxygen-rich Benguela Current runs along the coast from Antarctica.
The Southern region is also distinguished by colossal fish productivity. Kuril Islands, where the cold current passes over the submeridional marginal ocean rift Jonah. At the height of the saury season, literally the entire Far Eastern fishing fleet of Russia gathers in a small water area of the South Kuril Strait. It is appropriate here to recall Kuril Lake in Southern Kamchatka, where one of the largest spawning grounds of sockeye salmon is located in our country (sp. Far Eastern salmon). The reason for the very high biological productivity of the lake, according to experts, is the natural “fertilization” of its water with volcanic emanations (it is located between two volcanoes - Ilyinsky and Kambalny).
However, let's return to El Niño. During the period when degassing intensifies off the coast of South America, the thin, oxygenated and teeming with life surface layer of water is blown through with methane and hydrogen, oxygen disappears, and the mass death of all living things begins: from the bottom of the sea, trawls lift a huge number of bones of large fish, onto Seals are dying on the Galapagos Islands. However, it is unlikely that the fauna is dying due to a decrease in ocean bioproductivity, as the traditional version says. She is most likely poisoned by poisonous gases rising from the bottom. After all, death comes suddenly and overtakes the entire marine community - from phytoplankton to vertebrates. Only birds die from hunger, and even then mostly chicks - adults simply leave the danger zone.
"RED TIDES"
However, after the mass disappearance of the biota, the amazing riot of life off the western coast of South America does not stop. In oxygen-deprived waters blown with toxic gases, single-celled algae - dinoflagellates - begin to rapidly develop. This phenomenon is known as "red tide" and is so named because only intensely colored algae thrive in such conditions. Their color is a kind of protection from solar ultraviolet radiation, acquired back in the Proterozoic (over 2 billion years ago), when there was no ozone layer and the surface of reservoirs was subjected to intense ultraviolet irradiation. So during “red tides” the ocean seems to return to its “pre-oxygen” past. Due to the abundance of microscopic algae, some marine organisms that usually act as water filters, such as oysters, become poisonous at this time and their consumption can lead to severe poisoning.
Within the framework of the gas-geochemical model I developed for the anomalous bioproductivity of local areas of the ocean and the periodically rapid death of biota in it, other phenomena are also explained: the massive accumulation of fossil fauna in ancient shales of Germany or phosphorites of the Moscow region, overflowing with the remains of fish bones and cephalopod shells.
MODEL CONFIRMED
I will give some facts indicating the reality of the El Niño degassing scenario.
During the years of its manifestation it increases sharply seismic activity The East Pacific Rise - this was the conclusion made by the American researcher D. Walker, having analyzed the relevant observations from 1964 to 1992 in the area of this underwater ridge between 20 and 40 degrees. w. But, as has long been established, seismic events are often accompanied by increased degassing of the earth’s interior. The model I developed is also supported by the fact that the waters off the western coast of South America literally boil with the release of gases during El Niño years. The hulls of ships are covered with black spots (the phenomenon is called “El Pintor”, translated from Spanish as “the painter”), and the foul smell of hydrogen sulfide spreads over large areas.
In the African Gulf of Walvis Bay (mentioned above as an area of anomalous bioproductivity), environmental crises also periodically arise, following the same scenario as off the coast of South America. Emissions of gases begin in this bay, which leads to massive fish deaths, then “red tides” develop here, and the smell of hydrogen sulfide on land is felt even 40 miles from the coast. All this is traditionally associated with the abundant release of hydrogen sulfide, but its formation is explained by the decomposition of organic residues on the seabed. Although it is much more logical to consider hydrogen sulfide as a common component of deep emanations - after all, it comes out here only above the fault zone. The penetration of gas far onto land is also easier to explain by its arrival from the same fault, tracing from the ocean to the interior of the continent.
It is important to note the following: when deep gases enter ocean water, they are separated due to sharply different (by several orders of magnitude) solubility. For hydrogen and helium, it is 0.0181 and 0.0138 cm 3 in 1 cm 3 of water (at temperatures up to 20 C and a pressure of 0.1 MPa), and for hydrogen sulfide and ammonia it is incomparably greater: 2.6 and 700 cm, respectively 3 in 1 cm 3 . That is why the water above the degassing zones is greatly enriched with these gases.
A strong argument in favor of the El Niño degassing scenario is a map of the average monthly ozone deficit over equatorial region planet, compiled at the Central Aerological Observatory of the Hydrometeorological Center of Russia using satellite data. It clearly shows a powerful ozone anomaly over the axial part of the East Pacific Rise slightly south of the equator. I note that by the time the map was published, I had published a qualitative model explaining the possibility of destruction of the ozone layer above this zone. By the way, this is not the first time that my predictions of the location of the possible appearance of ozone anomalies have been confirmed by field observations.
LA NINA
This is the name of the final phase of El Niño - a sharp cooling of water in the eastern part of the Pacific Ocean, when for a long period its temperature drops several degrees below normal. A natural explanation for this is the simultaneous destruction of the ozone layer both over the equator and over Antarctica. But if in the first case it causes heating of the water (El Niño), then in the second it causes a strong melting of ice in Antarctica. The latter increases the influx cold water into the Antarctic waters. As a result, the temperature gradient between the equatorial and southern parts of the Pacific Ocean sharply increases, and this leads to an intensification of the cold Peruvian Current, which cools the equatorial waters after the weakening of degassing and restoration of the ozone layer.
THE RIGITAL CAUSE IS IN SPACE
First, I would like to say a few “justifying” words about El Niño. The media, to put it mildly, are not entirely right when they accuse him of causing disasters such as floods in South Korea or unprecedented frosts in Europe. After all, deep degassing can simultaneously increase in many areas of the planet, which leads there to the destruction of the ozonosphere and the appearance of anomalous natural phenomena, which have already been mentioned. For example, the heating of water that precedes the occurrence of El Niño occurs under ozone anomalies not only in the Pacific, but also in other oceans.
As for the intensification of deep degassing, it is determined, in my opinion, by cosmic factors, mainly by the gravitational effect on the liquid core of the Earth, where the main planetary reserves of hydrogen are contained. An important role in this probably plays relative position planets and, first of all, interactions in the Earth - Moon - Sun system. G.I. Voitov and his colleagues from the Joint Institute of Physics of the Earth named after. O. Yu. Schmidt of the Russian Academy of Sciences established long ago: degassing of the subsoil noticeably increases during periods close to the full moon and new moon. It is also influenced by the position of the Earth in its circumsolar orbit and by changes in its rotation speed. The complex combination of all these external factors with processes in the depths of the planet (for example, the crystallization of its inner core) determines the pulses of increased planetary degassing, and hence the El Niño phenomenon. Its 2-7-year quasi-periodicity was revealed by domestic researcher N. S. Sidorenko (Hydrometeorological Center of Russia), having analyzed a continuous series of atmospheric pressure differences between the stations of Tahiti (on the island of the same name in the Pacific Ocean) and Darwin (northern coast of Australia) over a long period - since 1866 to the present time.
Candidate of Geological and Mineralogical Sciences V. L. SYVOROTKIN, Moscow State University. M. V. Lomonosova
The first time I heard the word “El Niño” was in the United States in 1998. At that time, this natural phenomenon was well known to Americans, but almost unknown in our country. And it’s not surprising, because El Niño originates in the Pacific Ocean off the coast of South America and greatly influences the weather in the southern states of the United States. El Niño(translated from Spanish El Niño- 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 Pacific Ocean, during which the area of heated surface water shifts to the east. (For reference: the opposite phase of oscillation - the displacement of surface waters to the west - is called La Niña (La Nina- baby, girl)). The El Niño phenomenon, which occurs periodically in the ocean, greatly affects the climate of the entire planet. One of the largest El Niño events occurred 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 between the Southern Oscillation and global changes climate. According to experts, warming El Niño phenomenon is one of the main driving forces natural variability in our climate.
In 2015 The World Meteorological Organization said the premature El Niño, dubbed the “Bruce Lee,” could be one of the strongest since 1950. Its appearance was expected last year, based on data on rising air temperatures, but these models did not materialize, and El Niño did not manifest itself.
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 possible development El Niño in 2015-2016. The report is published on the NOAA website. The conclusions of this document state that the conditions for the formation of El Niño are currently in place, and the average surface temperature of the equatorial Pacific (SST) is elevated and continues to rise. The probability that El Niño will develop throughout the winter of 2015-2016 is 95% . A gradual decline of El Niño is predicted in the spring of 2016. The report published an interesting graph showing the change in SST since 1951. Blue areas correspond to low temperatures (La Niña), orange indicates high temperatures (El Niño). The previous strong increase in SST of 2°C was observed in 1998.
Data obtained in October 2015 indicate that the SST anomaly at the epicenter already reaches 3 °C.
Although the causes of El Niño are not yet fully understood, it is known that it begins with trade winds weakening over several months. A series of waves move across the Pacific Ocean along the equator and create a body of warm water off South America, where the ocean normally has low temperatures due to the rise of deep ocean waters to the surface. Weakening trade winds coupled with strong westerly winds countering them could also create a paired cyclone (south and north of the equator), which is another sign of a future El Niño.
While studying the causes of El Niño, geologists noticed that the phenomenon occurs in the eastern part of the Pacific Ocean, where a powerful rift system has formed. American researcher D. Walker found a clear connection between increased seismicity on the East Pacific Rise and El Niño. Russian scientist G. Kochemasov saw another curious detail: the relief fields of ocean 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 expressed back in 1998. According to the scientist, powerful centers of hydrogen-methane degassing are located in hot spots of the ocean. Or simply - sources of constant release of gases from the bottom. Their visible signs- thermal water outlets, black and white smokers. In the area of the coasts of Peru and Chile, during El Niño years there is a massive release of hydrogen sulfide. The water is boiling and there is a terrible smell. At the same time, an amazing power 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 may have been caused by strong climate changes caused by El Niño. At the turn of the 9th and 10th centuries AD, the two largest civilizations of that time ceased to exist on opposite ends of the earth almost simultaneously. We are talking about the Mayan Indians and the fall of the Chinese Tang Dynasty, which was followed by a period of internecine strife. Both civilizations were in monsoon regions, the moisture of which depends on seasonal precipitation. However, a time came when the rainy season was unable to provide sufficient moisture for the development of agriculture. The drought and subsequent famine led to the decline of these civilizations, researchers believe. Scientists came to these conclusions by studying the nature of sedimentary deposits in China and Mesoamerica dating back to this 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 could 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 nitrate, iodine, table salt and copper; for four centuries there has been no significant precipitation. The reason is that the Peruvian Current cools the lower layers of the atmosphere and creates a temperature inversion that 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 faded plains of the Atacama were covered with yellow, red, violet and white flowers - nolans, beaumaries, rhodophials, fuchsias and hollyhocks. The desert first bloomed in March, after unexpectedly intense rains caused flooding in the Atacama and killed about 40 people. Now the plants have bloomed for the second time in a year, before the start of the southern summer.
What will El Niño 2015 bring? A powerful El Niño is expected to bring welcome rainfall to dry areas of the United States. In other countries, its effect may be the opposite. In the western Pacific Ocean, El Niño creates high atmospheric pressure, bringing dry and sunny weather to large areas of Australia, Indonesia, and sometimes even India. The impact of El Niño on Russia has so far been limited. It is believed that under the influence of El Niño in October 1997, Western Siberia The temperature settled above 20 degrees, and then they started talking about the retreat of permafrost to the north. In August 2000, Emergencies Ministry specialists attributed the series of hurricanes and rainstorms that swept across the country to the impact of the El Niño phenomenon.
After a period of neutrality in the El Niño-La Niña cycle observed in mid-2011, tropical zone The Pacific Ocean began to cool in August and a weak to moderate La Niña has been observed from October until now.
“Mathematical model forecasts and expert interpretation suggest that La Niña is near maximum strength and is likely to slowly weaken in the coming months. However, existing methods do not allow predicting the situation beyond May, so it is unclear what situation will develop in the Pacific Ocean - whether it will be El Niño, La Niña or a neutral situation,” the report says.
Scientists note that La Niña 2011-2012 was significantly weaker than in 2010-2011. Models predict that temperatures in the Pacific Ocean will approach neutral levels between March and May 2012.
La Niña 2010 was accompanied by a decrease in cloud cover and increased trade winds. The decrease in pressure led to heavy rain in Australia, Indonesia and 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 drought situation in the central regions of southwest 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 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 an area of heated surface water moves eastward. At the same time, trade winds weaken or stop altogether, and upwelling slows down in the eastern part of the Pacific Ocean, off the coast of Peru. The opposite phase of oscillation is called La Niña (Spanish: La Niña - Baby, Girl). The characteristic oscillation time is from 3 to 8 years, but the strength and duration of El Niño in reality varies greatly. Thus, in 1790-1793, 1828, 1876-1878, 1891, 1925-1926, 1982-1983 and 1997-1998, powerful phases of El Niño were recorded, while, for example, in 1991-1992, 1993, 1994 this phenomenon , often repeating, 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 change 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 to the west, along the equator, cold and plankton-rich waters rise 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. Trade winds drive the heated surface layer of water into the western zone of the tropical Pacific Ocean, where the so-called tropical warm pool (TTB) is formed. In it, the water is heated to depths of 100-200 m. The Walker atmospheric circulation, manifested in the form of trade winds, coupled with low pressure over the Indonesian 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 versus 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 water temperatures are rising across a vast 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 and showers to the deserts, even causing 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 northerly current "El Niño" because it was most noticeable on days Catholic Christmas. In 1893, Charles Todd suggested that droughts in India and Australia were occurring at the same time. Norman Lockyer also pointed out the same thing in 1904. The connection between the warm northerly current off the coast of Peru and floods in that country was reported in 1895 by Peset and Eguiguren. The phenomena of the Southern Oscillation were first described in 1923 by Gilbert Thomas Walker. He introduced the terms Southern Oscillation, El Niño and La Niña, and examined 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 regional. Only towards the end of the 20th century. The connection between El Niño and the planet's climate has been clarified.
QUANTITATIVE DESCRIPTION
Currently, for a quantitative description of the phenomena, El Niño and La Niña are defined as temperature anomalies of the surface layer of the equatorial part of the Pacific Ocean lasting at least 5 months, expressed in a deviation of water temperature by 0.5 °C higher (El Niño) or lower (La Niña) side.
First signs of El Niño:
Increase in air pressure above Indian Ocean, Indonesia and Australia.
A 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 cease and the wind direction changes to the westerly.
Warm air mass in Peru, rains in the Peruvian deserts.
In itself, an increase in water temperature off the coast of Peru by 0.5 °C is considered only a condition for the occurrence of El Niño. Typically, such an anomaly can exist for several weeks and then disappear safely. 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 indexes indicate the El Niño phase, and positive ones indicate the La Niña phase.
INFLUENCE OF EL NINO ON THE CLIMATE OF DIFFERENT REGIONS
In South America, the El Niño effect is most pronounced. This phenomenon typically causes warm and very humid summer periods (December to February) along the northern coast of Peru and Ecuador. When El Niño is strong, it causes severe flooding. This, for example, happened in January 2011. Southern Brazil and northern Argentina also experience wetter than usual periods, but mainly in the spring and early summer. Central Chile experiences mild winters with plenty of rain, while Peru and Bolivia occasionally experience unusual winter snowfalls for the region. Drier and warmer weather is observed in the Amazon, Colombia and Central America. Humidity is falling in Indonesia, increasing the likelihood of forest fires. 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 western Antarctic Peninsula, Ross Land, Bellingshausen and Amundsen seas are covered with large amounts of snow and ice. At the same time, the pressure increases and becomes warmer. In North America, winters generally become warmer in the Midwest and Canada. Central and southern California, northwestern Mexico and the southeastern United States are becoming wetter, while the Pacific Northwest states are becoming drier. During La Niña, on the other hand, the Midwest becomes drier. El Niño also leads to a decrease in Atlantic hurricane activity. Eastern Africa, including Kenya, Tanzania and the White Nile Basin, experiences long rainy seasons from March to May. Droughts plague southern and central Africa from December to February, mainly Zambia, Zimbabwe, Mozambique and Botswana.
An El Niño-like effect is sometimes observed in the Atlantic Ocean, where water along the equatorial coast of Africa becomes warmer and water off the coast of Brazil becomes colder. Moreover, there is a connection between this circulation and El Niño.
INFLUENCE OF EL NINO ON HEALTH AND SOCIETY
El Niño causes extreme weather conditions associated with cycles in the incidence of epidemic diseases. El Niño is associated with an increased risk of mosquito-borne diseases: malaria, dengue fever and Rift Valley fever. Malaria cycles are associated with El Niño in India, Venezuela and Colombia. There is an association with outbreaks of Australian encephalitis (Murray Valley Encephalitis - MVE) occurring in south-eastern Australia following heavy rainfall and flooding caused by La Niña. A notable example is the severe outbreak of Rift Valley fever that occurred due to El Niño following extreme rainfall events 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 is influenced by El Niño. A study of data from 1950 to 2004 found that El Niño was associated with 21% of all civil conflicts during that period. Moreover, the risk of civil war during El Niño years is twice as high as during La Niña years. It is likely that the connection between climate and military action is mediated by crop failures, which often occur in hot years.
The climate phenomenon La Niña, associated with a drop in water temperatures in the equatorial Pacific Ocean and influencing weather patterns across almost the entire globe, has disappeared and is not likely to return until the end of 2012, the World Meteorological Organization (WMO) said.
The La Nina phenomenon (La Nina, “the girl” in Spanish) is characterized by an anomalous decrease in surface water temperature in the central and eastern part of the tropical Pacific Ocean. This process is the opposite of El Niño (El Nino, “the 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.
Following a period of neutrality in the El Niño-La Niña cycle observed in mid-2011, the tropical Pacific began to cool in August, with weak to moderate La Niña observed from October to date. By early April, La Niña had completely disappeared, and neutral conditions are still observed in the equatorial Pacific, experts write.
“(Analysis of modeling results) suggests that La Niña is unlikely to return this year, while the probabilities of remaining neutral and El Niño occurring in the second half of the year are approximately equal,” the WMO said.
Both El Niño and La Niña influence circulation patterns of ocean and atmospheric currents, which in turn influence weather and climate across the globe, causing droughts in some regions and hurricanes and heavy rainfall in others.
The La Niña climate phenomenon that occurred in 2011 was so strong that it ultimately caused global sea levels to drop by as much as 5 mm. With the advent of La Niña, there was a shift in Pacific surface temperatures and changes in precipitation patterns around the world, as terrestrial moisture began to leave the ocean and be directed to land in the form of rain in Australia, northern South America, and Southeast Asia .
The alternating dominance of the warm oceanic phase of the Southern Oscillation, El Niño, and the cold phase, La Niña, can change global sea levels so dramatically, but satellite data inexorably indicates that global levels have The waters still rise to a height of about 3 mm.
As soon as El Niño arrives, the rise in water levels begins to occur faster, but with a change in phases almost every five years, a diametrically opposite phenomenon is observed. The strength of the effect of a particular phase also depends on other factors and clearly reflects the general climate change towards its harshness. Many scientists around the world are studying both phases of the southern oscillation, as they contain many clues to what is happening on Earth and what awaits it.
A moderate to strong La Niña atmospheric phenomenon will continue in the tropical Pacific until April 2011. This is according to an El Niño/La Niña advisory issued on Monday by the World Meteorological Organization.
As the document highlights, all model-based forecasts predict a continuation or possible intensification of the La Niña phenomenon over the next 4-6 months, ITAR-TASS reports.
La Niña, which this year formed in June-July, replacing the El Niño phenomenon that ended in April, is characterized by unusually low water temperatures in the central and eastern equatorial parts of the Pacific Ocean. This disrupts normal tropical precipitation and atmospheric circulation patterns. El Niño is exactly the opposite phenomenon, which is characterized by unusual high temperatures waters 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 temperature. Typically, La Niña results in heavy winter rainfall in the eastern equatorial Pacific, Indonesia, and the Philippines, and severe droughts in Ecuador, northwestern Peru, and eastern equatorial Africa.
In addition, the phenomenon contributes to a decrease in global temperatures, and this is most noticeable from December to February in northeastern Africa, Japan, southern Alaska, central and western Canada, and southeastern Brazil.
The World Meteorological Organization (WMO) said today in Geneva that in August this year, the La Niña climate phenomenon was again observed in the equator region of the Pacific Ocean, which may increase in intensity and continue until the end of this year or the beginning of next year.
In the latest WMO report on El Niño phenomena and La Niña, it is said that the current La Niña phenomenon will peak later this year, but the intensity will be less than it was in the second half of 2010. Due to its uncertainty, WMO invites countries in the Pacific region to closely monitor its development and promptly report on possible droughts and floods due to it.
The La Niña phenomenon refers to the phenomenon of an anomalous long-term 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 spring drought along the western Pacific coast, including China.
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