Influence of El Nino Phenomenon on Climate in China

According to the introduction of China Meteorological Bureau on June 3rd 165438+, at present, the equatorial Middle East Pacific has entered the El Ni? o state, and an El Ni? o event is about to form. This El Ni? o event will have two impacts on China's climate, namely, there is more precipitation in the south and warm winters in most parts of the central and eastern regions.

1, there will be more precipitation in the south.

Under the background of El Nino, the South China Sea and the North Pacific Ocean are easy to arouse the circulation of anticyclone system, which is conducive to the transport of tropical warm and humid water vapor to the south of China, and it is easy to cause excessive precipitation in the south with the cooperation of cold air activities. Therefore, it is suggested to pay close attention to the possible adverse effects of the staged low-temperature rain and snow weather process.

2. There will be a warm winter in most parts of the central and eastern regions.

Affected by El Nino, abnormal anticyclonic circulation prevails in the lower troposphere over the northwest Pacific and South China Sea in winter, and the East Asian trough is weak, and the winter monsoon in East Asia is weak, which leads to warmer temperatures in most parts of central and eastern China and a warm winter phenomenon. Recently, the temperature in the northern region is unusually high, and the highest temperatures in Hebei, Shandong, Henan and other places even reach 30 degrees Celsius, far exceeding the same period last year.

Reasons for the formation of El Nino phenomenon:

1. Abnormal rise of SST in tropical Pacific: El Ni? o usually occurs in equatorial, middle east and Pacific regions. When the sea surface temperature in this area rises abnormally, it will trigger the El Ni? o phenomenon. This abnormal increase in SST usually occurs in summer or autumn.

2. Changes of atmospheric circulation: The abnormal increase of SST in the equator and the Middle East Pacific will lead to changes of atmospheric circulation. Under normal circumstances, the atmospheric circulation in the equatorial region is the northeast wind from east to west, but in the El Ni? o event, this atmospheric circulation will weaken or even reverse, forming an airflow from west to east.

3. Tropical convection changes: El Ni? o phenomenon will also lead to convection changes in tropical areas. Under normal circumstances, convection in tropical areas is mainly concentrated in the western Pacific Ocean, but in El Ni? o events, convection will move eastward and concentrate in the Middle East and the Pacific Ocean.