What effects does El Nino have on the climate in China, and in what ways?

In winter, the Asian continent is controlled by the strong Siberian cold high pressure, while the ocean is much warmer and the air pressure is relatively low, and the air flows from the high pressure part to the low pressure part and from the mainland to the ocean. Therefore, the northwest airflow from high latitudes prevails in most parts of our country, and the cold wave and cold air pass by, and the climate is cold and dry. The intensity of winter wind is the direct cause of cold and warm weather in China. The research shows that in winter of El Nino, the location of polar front in East Asia is often northward, and the cold air activity is also northward.

Impact 2: Drought and flood

In the summer of El Nino, due to the increase of SST in the equatorial eastern Pacific and the strengthening of Hadley circulation, the intensity of subtropical high leading to the Pacific Ocean increased. However, with the decrease of SST in the western Pacific and the weakening of atmospheric convection, the subtropical high is located to the south. The research shows that the response of the western Pacific subtropical high to El Nino is several months behind, so the correlation is more obvious in the second year of El Nino. In addition, due to the influence of the circulation situation, the cold air activity is relatively southward, and the summer monsoon is weak, so the monsoon rain belt produced by the convergence of cold and warm air is also southward, which makes the middle and lower reaches of the Yangtze River rainy and even occur.

In addition, the study shows that in the autumn and winter when El Nino occurs, the precipitation distribution pattern in the eastern part of China is easy to appear, that is, the precipitation in most parts of the north is less than normal, and the precipitation in most parts of the south is more than normal.

Impact three. Northeast Leng Xia

El Nino is also related to the summer temperature in Northeast China. Statistics show that in the summer when El Nino occurs, the cold air activity in Northeast China is often strengthened, which leads to abnormally low summer temperature in Northeast China, resulting in low temperature and chilling injury, resulting in reduced grain production.

Impact 4. Tropical storms have decreased.

Most tropical cyclones in the northwest Pacific are developed from low clouds and clouds in intertropical convergence zone. When El Nino occurs, the equatorial eastern Pacific warms, the tropical northwest Pacific cools, and the atmospheric stability increases, which is not conducive to the development of cumulus convection in the tropical Pacific. The number of tropical storms and typhoons will also decrease accordingly, and the number of landings in China will be less than normal.