An "uninvited guest" broke in here. In an instant, almost all cold water plankton lost their lives, most carp died in batches, and many seabirds starved to death because of lack of food ... Within a few days, the sea was covered with fish and seabirds. They decompose and produce a large amount of hydrogen sulfide, which causes the seawater to smell abnormal and turn black quickly. The hulls of the ships that came here, even the rocks on the coast, were dyed black, as if painted with a layer of black paint. The combination of hydrogen sulfide and sea fog drifted with the wind, and the houses and cars in callao, the outer port of Lima, Peru, were also dyed black. So the local people nicknamed the black sea water and black fog "callao painter". So far, when you sail to the coastal areas of callao, you will find that the color of sea water here is different from other places, just like a pot of soy sauce soup.
A large number of fish and seabirds died, resulting in a sharp decline in Peru's fishery production; The fishmeal processing factory with glue fish as raw material was forced to stop work and the workers were unemployed; The guano industry has also suffered serious losses.
Who created this disaster? It turned out to be a small warm current, which people called "El Nino".
"El Nino" is Spanish, which literally means "Son of Jesus" or "El Nino". Although its name is beautiful, its behavior is ugly. In people's eyes, he is a "bad boy" who specializes in practical jokes. Whenever it visits a fishing ground in western Peru, it will bring disaster to marine life. Most of the most terrible disasters happened around the Christmas of Jesus Christ 65438+February 25th. Therefore, Peruvians call this natural phenomenon El Nino.
El Nino's hometown is in the equatorial waters of the eastern Pacific Ocean, where it is warm all the year round and the water temperature is high. The equatorial countercurrent initially flows steadily from west to east. It happened that at some point, this equatorial countercurrent also bifurcated, and some seawater went south along the coast of Ecuador, crossed the equator, and entered the Peruvian fishing ground, causing the seawater temperature here to suddenly rise by 3℃~5℃, and sometimes even as high as 8℃, which brought great disasters to many cold-water fish.
El Nino was originally a "patent" in some waters of Peru. It is reported that in Peru, El Ni? o means "warm water invading south". Later, scientists discovered that. El Nino not only brings disaster to Peru's marine life, but also affects the global climate, causing the earth to launch "malaria". It caused sudden rainstorm in arid areas, and made the places with abundant rainfall dry for a long time. It makes the cold winter months warm like spring, and makes the hot season cold and clear.
The strongest El Nino in the 20th century occurred in 1982~ 1983. When El Nino came, the equatorial water temperature in the eastern Pacific suddenly rose by 6℃, and many countries in the world suffered unexpected abnormal climate and rare natural disasters in a hundred years. Drought occurred in 60% of Zimbabwe, and corn production decreased by 2/3, and 500,000 cattle died prematurely or were slaughtered due to drought.
Switzerland, which is famous for its beautiful weather, 1982 was overcast in spring, with a cold wind and sometimes heavy rain. The rainfall in the first half of May is rare for 46 years.
Since June 1982 and 1 1, the continuous rainstorm has brought unprecedented floods to Ecuador and other areas.
In short, El Nino caused economic losses of nearly10 billion US dollars, and more than 65,438+0,300 people were killed in natural disasters caused by El Nino.
The El Nino phenomenon, which started from April to May in 1997, is no less serious than the disaster brought to some parts of the world in the early 1980s.
1997 65438+1At the end of October, southern Manitoba suffered the biggest flood in 70 years. More than 2,000 square kilometers of farmland and villages and towns in Fiona Fang have become Zeguo, and 25,000 people have been displaced.
September14 ~16; Typhoon Oliva hit Kyushu Island in southern Japan with a wind speed of-0/58km per hour, killing four people, forcing tens of thousands of people to move and flooding more than 500 houses across the country.
According to the statistics of the World Food and Agriculture Organization, due to the influence of El Ni? o in Southeast Asia, the Caribbean and South America, the total grain output decreased by 1996 15%. The number of countries threatened by famine has increased to 29, of which 65,438+08 are in Africa, 5 are in Asia and Eastern Europe, and 65,438+0 are in Latin America.
According to statistics, there were 12 El Nino events in the 20th century. They occurred in 1925, 194 1, 1957~ 1958, 1965,1972 ~1respectively. 1986~ 1987, 199 1, 1992, 1994~ 1995, 1997.
Judging from the above statistics, since the 1990s, El Ni? o has appeared frequently with shorter intervals.
How is the El Nino warm current produced? Although scholars from all over the world have conducted extensive research, they still have not fully understood its mechanism and failed to decipher its "password".
Some people think that it is caused by the abnormal weakening of the southeast trade winds, and intertropical convergence zone moves south and crosses the equator. Others believe that it is due to the weakening of circulation. For a long time, the air mass parallel to the coast weakened, so the upwelling also weakened or even stopped. As a result, the El Ni? o warm current will take advantage of it.
Others believe that the meteorological factors that control the El Ni? o warm current make the Pacific trade winds fluctuate slightly. Due to the massive accumulation of tropical warm water masses in the East Pacific, the south wind disappeared, and the warm tropical water covered the cold water flowing from Peru, resulting in the El Ni? o warm current.
Daniel Walker, an American geophysicist, suggested that the main driving force of El Ni? o was the hot lava emitted by the structural plate at the bottom of the Pacific Ocean. They heated the seawater above the lava, making its temperature rise enough to affect the surface temperature of the ocean, which triggered the El Ni? o phenomenon.
Wang Yongji, a researcher at the First Institute of Oceanography of the State Oceanic Administration of China, and Lu, an associate researcher, have found that the position between the sun, the moon and the earth is closely related to El Ni? o through the analysis of a large number of marine survey data in recent years ... They think that the slow rotation of the earth and the rising sea temperature in the eastern Pacific Ocean are simultaneous. In 1968~ 1969, 1972~ 1973, 1975~ 1976, the equatorial current reached its peak. The influence of the change of the earth's rotation rate on the ocean and atmosphere mainly occurs in low latitudes. When the earth's rotation speed slows down, the sea water (atmosphere) near the equator gets more angular movement to the east, which weakens the equatorial current and produces a large number of equatorial currents to the east, making it difficult for the cold water rising along the coast of Ecuador and Peru to spread to the equator, thus accumulating warm water in the eastern Pacific Ocean and raising the sea water temperature, so El Ni? o occurs.
In the study, the two researchers also found that the distance between the moon and the earth above the equator has a period of 4.425 years. That is, every year 1.3 or 1.4 (a few days after Christmas) is the closest point of the moon from the earth. The relative motion of the sun, the moon and the earth occurs every 4.425 years. At this time, the astronomical tidal force increased significantly, which in turn affected the earth's rotation speed to slow down, and the seawater near the equator gained more angular movement to the east. At the same time, the equatorial current weakened and a large number of equatorial currents flowed eastward, which led to the accumulation of warm water in the eastern Pacific and the formation of El Ni? o.
In short, at present, some major countries in the world have invested a lot of manpower and material resources to study El Ni? o. I believe that one day, the "code" generated by El Ni? o will eventually be deciphered, and people can plan ahead.