Why has the weather become strange?

It should be El Nino phenomenon, also called El Nino current, which is a climatic phenomenon caused by the imbalance between the ocean and the atmosphere in the Pacific equatorial belt. Under normal circumstances, the monsoon air flow in the tropical Pacific moves from America to Asia, keeping the surface of the Pacific Ocean warm and bringing tropical rainfall around Indonesia. However, this pattern is disturbed every 2-7 years, and the wind direction and ocean current are reversed. The heat flow in the surface of the Pacific Ocean turns eastward to America, and then takes away tropical rainfall, resulting in the so-called "El Ni? o phenomenon". The word "El Nino" comes from Spanish, which means "El Nino". /kloc-At the beginning of the 9th century, in Spanish-speaking countries such as Ecuador and Peru in South America, fishermen found that every few years, that is, from June of 10 to March of the following year, a warm current moved southward along the coast, which significantly increased the surface seawater temperature. The Peruvian cold current originally prevailed on the east coast of the Pacific Ocean in South America. Fish that move with the cold current make Peru's fishing ground one of the three largest fishing grounds in the world. But when this warm current appears, a large number of fish who like cold water will die, leading to the extinction of fishermen. Because this phenomenon is often the most serious around Christmas, fishermen who suffer from natural disasters and are helpless are called the son of God-El Nino. Later, in science, the term was used to indicate the abnormal warming of sea surface temperature in the eastern Pacific Ocean thousands of kilometers near Peru and Ecuador. When this happens, the sea water temperature in a wide range can be 3-6 degrees Celsius higher than normal. The rising water temperature in the vast waters of the Pacific Ocean has changed the traditional equatorial currents and southeast trade winds, resulting in global climate anomalies. The basic feature of El Nino phenomenon is that the sea surface temperature along the Pacific coast rises abnormally, the sea water level rises, and a warm current flows southward. It turns cold water in the East Pacific into warm water, causing tsunamis and storms, causing drought in some areas and excessive rainfall in others. The whole process of El Nino is divided into occurrence period, development period, maintenance period and attenuation period, which generally lasts for about one year, and the change of atmosphere lags behind the change of seawater temperature. Today, with the highly developed meteorological science, people have understood that the central Pacific Ocean is the main power source of summer climate change in the northern hemisphere. Usually, there is a northward Peruvian cold current in the Pacific Ocean on the west side of the South American continent, and part of it turns into an equatorial flow and moves westward. At this time, the monsoon blowing westward along the sea near the equator makes the warm current accumulate to the west side of the Pacific Ocean, while the low-level cold sea water rises to the east side, which makes the sea temperature in the western Pacific Ocean south of the Philippines and north of New Guinea rise. This part of the sea area is called "equatorial warm pool", and the seawater temperature in the east of the same latitude is relatively low. There is also a temperature difference in the atmosphere over the two sea areas. The temperature in the east is low and the air pressure is high, and the cold air sinks and flows westward. The temperature in the west is high and the air pressure is low. After the hot air rises, it turns to the east. In this way, an atmospheric circulation (Walker circulation) is formed in the middle of the Pacific Ocean, and the southeast trade wind is formed near the sea level. But sometimes, this pressure difference will be lower than the multi-year average, and sometimes it will increase. This phenomenon of atmospheric change is called "Southern Oscillation". In 1960s, meteorologists found that El Nino was closely related to the Southern Oscillation. When the pressure difference decreased, El Nino appeared. After El Nino, due to the warming of warm current, the monsoon flowing from east to west in the Pacific Ocean was greatly weakened, which significantly changed the atmospheric circulation and greatly affected the climate of countries along the Pacific Ocean. The originally wet area was dry, and there was a flood in the dry area. When this pressure difference increases, the seawater temperature will drop abnormally, which is called "La Nina phenomenon".