Explanation of El Nino phenomenon

El Nino, also known as El Nino, is a term used by fishermen in Peru and Ecuador to refer to an abnormal climate phenomenon. It is called ENSO together with another phenomenon-Southern Oscillation. El Nino is a climatic phenomenon, which occurs in the tropical Pacific Ocean, where the sea surface temperature is unusually warm. Large-scale warming of tropical Pacific will cause global climate change.

First of all, briefly introduce the Nilno phenomenon:

El Nino is a climatic phenomenon, which occurs in the tropical Pacific Ocean, where the sea surface temperature is unusually warm. Large-scale warming of tropical Pacific will cause global climate change.

El Nino is an abnormal natural phenomenon in the Pacific Ocean. On the west coast of South America and the eastern part of the South Pacific, there is a famous Peruvian cold current flowing from south to north. June165438+1October is the summer in the southern hemisphere. The water temperature in the southern hemisphere generally rises, and the equatorial warm current flowing westward strengthens.

At this time, the global pressure belt and wind belt move south, and the northeast trade wind passes through the equator and is deflected to the left by the self-deflection force of the southern hemisphere into the northwest monsoon, which is also called geostrophic deflection force.

The northwest monsoon not only weakens the near-sea breeze and southeast wind trade winds on the west coast of Peru, but also weakens or even disappears the cold water flood of Peru's cold current, and also blows the equatorial warm current with higher water temperature to the south, making the water temperature of Peru's cold current abnormally high. This kind of ocean current, which comes quietly and is not fixed, is called El Nino Warm Current.

Second, the weather phenomenon:

The upwelling cold seawater is rich in nutrients, which makes plankton multiply in large numbers and provides sufficient bait for fish. The prosperity of fish provides rich food for fish-eating birds, so there are many birds. When the southeast trade winds are abnormally strengthened, the upwelling of seawater in the equatorial eastern Pacific is extremely strong and the precipitation is abnormally low, while the seawater temperature in the equatorial western Pacific is abnormally high and the precipitation is abnormally high.

Due to high seawater temperature, unstable air stratification and convection development, the east coast of equatorial Pacific changed from dry and rainy to rainy, causing floods, while the west coast of equatorial Pacific changed from wet and rainy to dry and rainy because of low seawater temperature and stable air stratification.

When El Nino appears, it will cause continuous low temperature in the Japanese archipelago and Northeast China in summer, and precipitation tends to be less in most parts of China in some years.