Geographical terms of climate anomaly in a certain year

Geographically called climate anomaly, there is no technical term. The global climate anomalies often mentioned are mainly El Nino and La Nina.

1, El Nino (Spanish: El Nino? O), also known as El Nino phenomenon and Southern Oscillation. This is a term used by fishermen in Peru and Ecuador to refer to abnormal climate phenomena. It mainly refers to the abnormal continuous warming of seawater temperature in the tropical ocean in the eastern and central Pacific Ocean, which changes the global climate pattern, causing drought in some areas and excessive rainfall in some areas.

For China, El Ni? o is prone to warm winters, heavy rains and floods in the south, high temperature and drought in the north and Leng Xia in the northeast. Extreme weather is more dangerous than simple temperature changes. (1) Reduce typhoons. The number of tropical storms (typhoons) in the western Pacific and the number of coastal landings in China are less than normal. ② The summer monsoon is weak, and the monsoon rain belt is southerly, which is located in the middle of China or south of the Yangtze River. The northern region is prone to drought and high temperature in summer, while the southern region is prone to low temperature and flood. In the past century, serious floods in China, such as 193 1, 1954, 1998 in the middle and lower reaches of the Yangtze River, all occurred one year after the El Ni? o phenomenon. ③ In the winter after El Nino, it is easy to have a warm winter in northern China.

2. La Nina refers to the phenomenon that the sea surface temperature in the eastern and central equatorial Pacific is unusually cold (just the opposite of El Ni? o phenomenon), which is the product of the interaction between tropical ocean and atmosphere. La Nina means "La Nina" in Spanish? A "-"little girl, saint "means the reverse of El Ni? o phenomenon, also known as" anti-El Ni? o "or" cold event ". It refers to the abnormal drop of water temperature in the eastern Pacific near the equator, which is characterized by the obvious cooling of the eastern Pacific and the global climate chaos, and always appears after the El Ni? o phenomenon.

La Nina has an influence on the summer temperature in Northeast China. In La Nina year, the summer temperatures in Shenyang, Changchun and Harbin are high, and in El Ni? o year, the summer temperatures are often low. Northeast China is one of the main grain producing areas in China, and the temperature change has certain influence on the grain output there. La Nina also has an impact on precipitation in flood season in North China. During La Ni? a, the precipitation in flood season in North China tends to be more, and the annual precipitation in El Ni? o tends to be less, which is related to the location of the western Pacific subtropical high. The position of La Nina subtropical high in the north is beneficial to the formation of rainy atmospheric circulation situation in North China in flood season, while the position of El Ni? o subtropical high in the south is unfavorable to the establishment of rainy atmospheric circulation situation in North China in flood season.