What is the El Nino phenomenon?

El Nino phenomenon refers to the large-scale abnormal warming of seawater in the tropical Pacific Ocean. This phenomenon leads to the rise of the earth's temperature, which makes various factors affecting the climate unbalanced, thus leading to climate anomalies. According to historical records, since 1950, there have been 13 El Nino phenomena all over the world. The one that happened in 1997 and continues to this day is the most serious. Mainly manifested in: from the northern hemisphere to the southern hemisphere, from Africa to Latin America, the climate has become weird and incredible. The cool place is like fire, and it suddenly snows in warm spring. When the rainy season comes, it doesn't rain, and the dry season floods. ...

Because tropical marine areas receive more solar radiation, the seawater temperature is correspondingly higher. In the tropical Pacific Ocean, the equatorial current flows from the eastern Pacific Ocean to the western Pacific Ocean due to the traction of the east equatorial trade wind, which makes the high warm current in the western Pacific Ocean accumulate continuously and become the highest sea surface temperature in the world, with the sea surface temperature above 29℃. On the contrary, the SST in the equatorial eastern Pacific is relatively low, generally 23 ~ 24℃. Due to the distribution characteristics of sea surface temperature field, the tropical western Pacific presents updraft and low pressure.

Under normal circumstances, the western Pacific has a strong upward movement and abundant precipitation. In the equatorial Middle East Pacific, the atmosphere is sinking and there is little precipitation. When the El Nino phenomenon occurs, a large amount of warm seawater flows from the equatorial western Pacific to the equatorial eastern Pacific, which leads to the decrease of seawater temperature, the weakening of atmospheric upward movement and the decrease of precipitation in the equatorial western Pacific, resulting in severe drought there. However, in the equatorial Middle East Pacific, due to the rising sea surface temperature, the upward movement is strengthened, which leads to an obvious increase in precipitation and heavy rain.

Scientists believe that the occurrence of El Nino phenomenon is related to the deterioration of human natural environment, the direct result of the intensification of global greenhouse effect, and the result of human beings demanding too much from nature and not paying attention to environmental protection.

The power of El Nino phenomenon

Scientists have recently noticed that due to the influence of the current El Ni? o phenomenon, the global temperature is rising, which leads to the acceleration of atmospheric wind speed and the slowdown of the earth's rotation. Compared with the physical planet Earth, El Nino accelerates the eastward movement of the atmosphere, thus bringing bad influence to the Earth. Through the analysis of the change of atmospheric angular momentum, the researchers show that the atmospheric angular momentum is always higher than the average from the middle of March 1997 to the end of March 10. In the era when there was no El Nino phenomenon, the winds in the tropics blew from east to west, while the winds in other parts of the earth blew from west to east. Their net momentum is the angular momentum from west to east. When the wind moves back and forth between the earth's surface and mountains, the atmosphere and this solid earth also exchange some momentum back and forth as usual. In winter in the northern hemisphere, the atmosphere accelerates and the earth slows down; In summer, the situation is just the opposite. Experts point out that El Nino increases the tropical area by slowing down the wind speed in the eastern part of the tropics.

External wind can increase atmospheric angular momentum. When El Nino broke out, with the acceleration of atmospheric wind, the rotation speed of the earth itself slowed down, so this mixed angular momentum was conserved. John of NASA Goddard Space Center? Gibson said that he observed the rotation of the earth by monitoring the length change during the day. In the past year, the daytime has been shortened and prolonged by about 1 millisecond, which is basically caused by the deviation of atmospheric angular momentum. Gibson said that in the current El Ni? o phenomenon, the day was extended by a quarter of a millisecond.

Interpretation of this autumn's strange weather experts analyzed that El Nino was the culprit.

News from the Northern Network: Although it has entered the early winter, the two consecutive "sneak attacks" of heavy rain, blizzard, thunderstorm, cold wave and storm surge have made this autumn unforgettable. Yesterday, the city meteorologists summarized and analyzed that this anomaly is mainly related to the circulation situation and sea surface temperature changes. According to the current data, it is probably a manifestation of El Nino.

The total precipitation is twice.

Under normal circumstances, autumn precipitation mainly appears in the form of light rain or light snow, moderate rain and medium snow are also rare, and heavy rain and heavy snow are even more difficult to see. This year, this series of abnormal weather is the prelude to a heavy rain. 65438+1October10-1There was a general rainstorm in Japan, and the urban precipitation reached 160.9mm only once, setting a historical record for the same period since 1887, while the previous record was only 4/.

From the statistics of September-165438+1October in the whole autumn, it can be seen that the precipitation in this city is as high as 222.8mm (in the urban area), which is nearly 60mm more than the precipitation extreme value 164.0mm set in the previous autumn of 1955, and 8/kloc with the 30-year average.

The history of snowfall accompanied by thunderstorms is rare. 1the first heavy snow in Japan came early on October 7 165438. Heavy snow and blizzard occurred in most districts and counties this time, with the daily snowfall in the urban area reaching 12.5mm, and the snowfall in Jixian County of this city reaching 20.7mm, setting a record for snowfall in the same period since 19 18. At the same time of snowfall, accompanied by a rare late autumn thunderstorm, a rare thunderstorm was formed, which once again rewritten the meteorological record of this city.

Storm surges hit Tianjin twice, around June 5438+1October 65438+1October 065438+1October 25 and around June 5438+1October 25. Under the combined action of astronomical tides and strong winds at sea, storm surges occurred twice in the coastal areas of this city, and the seawater obviously exceeded the warning water level and flooded into the block. Among them, the night when the storm surge occurred on1October 25th 165438+ set a new record for 19 18, which was higher than the latest1993+065438+/kloc-0.

The cold wave struck ahead of time.

Just after the Golden Week, there was a cold wave in North China, including this city, on June 65438+1October 65438+1October 0. According to the meteorological regulations, the lowest temperature in the morning of June 1 1 day in the urban area dropped to 4.7℃, and the average temperature of that day dropped from 17.2℃ the previous day to 7.3℃.

What is the El Nino phenomenon?

"El Nino" phenomenon is an abnormal warming phenomenon in the waters near the equator in the United States (4 degrees north latitude to 4 degrees south latitude and about 0/50 degrees west longitude to 90 degrees west longitude).

It turns out that the Pacific Ocean is not completely horizontal. In the Pacific Ocean in the southern hemisphere, as the strong southeast trade winds swept the northwest, the seawater was also pushed from the southeast to the west. Therefore, the ocean surface near Australia is about 50 cm higher than that in South America. At the same time, the cold water in the lower ocean along the coast of South America is constantly turning up, which has delivered a lot of nutrients to marine life such as fish and waterfowl here.

It is puzzling that this normal virtuous circle will be broken every few years. The southeast wind, which has always been strong, gradually weakens and may even reverse to the west wind. The upwelling of cold water along the eastern Pacific coast will also weaken or disappear completely. Therefore, the temperature of the upper seawater in the Pacific Ocean rises rapidly and flows back to the east. This rising El Ni? o ocean current will cause the sea level in the East Pacific to rise by 20-30 cm compared with the normal sea level, and the temperature will rise by 2-5 degrees Celsius. This abnormal temperature rise in turn heats the atmosphere, leading to unpredictable climate anomalies. For example, El Nino caused unprecedented droughts in southern Africa, Indonesia and Australia, and brought it to Peru.

In Ecuador and California, there are heavy rains, floods and mudslides. El Nino caused more than 65,438+0,500 deaths and 8 billion dollars in material losses. So far, scientists have not found an accurate answer about the cause of El Nino phenomenon. Some people think that the ocean current may be warmed by the volcanic eruption in the Pacific Ocean or the heating effect of lava ejected from the crustal fracture, which in turn leads to the weakening and reversal of the trade winds. Others infer that it may be caused by the uneven annual speed of the earth's rotation. They say that the interannual speed of the earth's rotation is caused by uneven acceleration. They say that every time the annual speed of the earth's rotation changes from acceleration to deceleration, it will happen.

El Nino phenomenon. Worryingly, El Nino phenomenon appears more and more frequently. Originally thought to come once every five years, seven years or even 10 years, it later appeared in a cycle of three to seven years. But since the 1990s, it seems to happen every two or three years.

Although the cause of El Nino phenomenon has not been ascertained, human beings have not resigned themselves to fate. 1986 foreign scientists successfully predicted the coming of El Nino one year in advance, and actively explored the relationship between greenhouse effect and El Nino phenomenon. It can be predicted that mankind will eventually be able to solve the mystery of nature that ravages mankind and find ways to avoid its harm.

The mystery of El Nino phenomenon

On the coast south of Lima, Peru, it is a rich and beautiful fishing ground. Thousands of seabirds inhabit coastal islands. These seabirds are numerous, flying around and buzzing.

Seabirds play in the sea and inhabit the island. They live here leisurely, and what makes them interested?

It turns out that the output of Peruvian fishing grounds is very high, and 10 has remained above 10 million tons for years. The ocean provides enough fish for seabirds to eat, and about 2.5 million tons of fish are eaten by seabirds every year.

From 1982 to 1983, an unusual thing happened. This year, the huge anchovies on the coast of Aco, Peru, quietly disappeared. Seabirds that feed on anchovies have also lost their food sources, dying and dying soon. The originally vibrant beach became desolate at this moment, leaving the remains of thousands of seabirds. Fishermen have no fish to catch, and the fishmeal factory has no raw materials and is on the verge of bankruptcy. Within a few days, the sea water also changed color. It turned out that a large number of dead fish and zooplankton covered the sea surface. Rotten organic matter fermentation produces a large amount of hydrogen sulfide gas, which makes seawater dirty and smelly. The combination of hydrogen sulfide and paint on the fishing boat shell produces lead sulfide, just like painting a fishing boat with black paint. The crew shook their heads and sighed, helpless. The fishing ground lost its vitality and prosperity in the past and fell into a dead silence.

What the hell is going on here? The reason was soon found out. Scientists who are in charge of investigating the mystery of the disappearance of anchovies have made a detailed investigation on the changes of seawater here. It turns out that in this cold water area, there has been an active warm current in recent days-El Nino. The sudden arrival of warm current raised the temperature of seawater by 3 ~ 6℃. Under the sudden attack of warm current, anchovies who are used to living in cold water can't stand it. They began to get sick and soon died in large numbers. The tragic fate of anchovies makes seabirds suffer greatly. They ate fish and soon starved to death on the beach.

Strangely, when the fish disaster occurred in Peru, the climate around the world and even the whole world was abnormal. In some places, it never rains once a year; Some places have been flooded repeatedly. It doesn't rain for a long time in many parts of Asia, and the weather is dry, just like barbecue; However, in some parts of Europe and America, heavy rains have caused disasters. ...

Why does the climate become crazy? People guessed the reason.

Some people say that frequent sunspot activities in those two years have caused changes in the weather system on the earth; It is also said that volcanic activity on the earth has increased, forming a volcanic ash layer in the air. The volcanic ash layer turned into many strange clouds. It has been floating over the earth for a long time, affecting climate change. ...

Their speculations are reasonable, but they always make people feel that the real cause of climate change has not been found.

Just when there was a serious fishing disaster in Peru, scientists studying abnormal weather also turned their attention to the unusual warm current. With the deepening of research, they are more and more convinced that the deterioration of global climate is related to this warm current.

Is it really El Nino that caused the climate madness? People opened the historical archives and the truth came out. In the archives, the year of abnormal climate is recorded; The year of El Nino activity is also recorded. People haven't studied their relationship before, but now they often appear one after another, and they actually cooperate so tacitly.

Why can an equatorial warm current in the East Pacific disturb the normal work of atmospheric circulation and affect climate change?

It turns out that the vast sea is the regulator of temperature and humidity on the earth. The main reason for the weather change is the uneven heating of the atmosphere. The ocean constantly provides heat to the atmosphere. As the temperature of the ocean itself rises, it provides more temperature for the atmosphere; On the contrary, when the temperature of the ocean itself drops, the heat it gives to the atmosphere decreases. The ocean is very big, and its heat capacity is greater than that of air. If the seawater of 1 cm3 is cooled to 1℃, the released heat can raise the atmospheric temperature of 3000 cm3 by 1℃. At the same time, seawater is a fluid, and the heat from the sea surface can be transferred to the deep layer, so that thick seawater can store heat. If the surface seawater at the depth of 100 meters in the global ocean is cooled 1℃, the released heat can be used to heat up the whole earth's atmosphere by 6℃.

Therefore, the warming of seawater in Peru has a great influence on the atmospheric circulation. Tropical oceans in the eastern and central Pacific Ocean have a more obvious impact on the earth's atmosphere. It not only affects the weather nearby, but also affects distant places and the whole earth through atmospheric circulation. El Nino, a small equatorial warm current, has affected the change of atmospheric stage, which is really disturbing!

Although the cause of climate madness has been found, if people can warn people all over the world in advance when the El Ni? o warm current is about to appear, people can be prepared to avoid disaster. How active that would be! But where is El Nino? This is an unpredictable trend. People only know that it appears about every few years, but they don't know the exact time when it appears.

Scientists study the causes of El Nino and try their best to find out its activity law. They studied in different fields and put forward different opinions on the formation of this warm current from various aspects. For example, some scientists believe that El Nino appears because the southeast wind trade winds on the earth are weakened; Some meteorologists say that the appearance of El Nino is related to the slowdown of the earth's rotation.

Not long ago, two American geologists put forward their own unique views. They used acoustic locators to measure the seabed of the Hawaiian Islands and the eastern Pacific Ocean. Through some information, they discovered the secrets of the seabed in this area. It turns out that there are many volcanoes under the sea here, and they are erupting a lot of lava. With the eruption of lava, huge hot fluid keeps pouring into the ocean, which raises the temperature of seawater. This phenomenon tells people that El Nino, a strange warm current that appears repeatedly in the eastern Pacific Ocean, may be the heat provided by submarine volcanic eruption.

Scientists have been paying close attention to the dynamics of this warm current, and are confident to uncover its secrets and accurately predict its arrival.