Why is Hainan so cold these days? ...

La Nina refers to the phenomenon that the sea surface temperature in the eastern and central equatorial Pacific Ocean continues to be abnormally cold (just the opposite of El Ni? o phenomenon). This is a new term used in meteorology and oceanography. It means "little girl", just the opposite of El Nino, which means "El Nino". It is also called "anti-El Nino" or "cold event". El Nino and La Nina are abnormal manifestations of alternating sea surface temperature in the equatorial, Middle East and Pacific Ocean, forming a cycle. La Nina phenomenon after El Nino is not uncommon. Similarly, La Nina will be followed by El Nino. However, according to the records since 1950, the frequency of El Nino is higher than that of La Nina. Under the background of global warming, the frequency and intensity of La Nina phenomenon are slowing down. Especially in the 1990s, there were three consecutive El Ni? os from 199 1 to 1995, but there was no La Ni? a in the middle.

La Nina is a modified transitional phenomenon after El Nino. This hydrological feature will cause the water temperature in the eastern Pacific to drop, which will lead to drought. On the contrary, the water temperature in the western Pacific will rise, and the precipitation will be significantly higher than normal. Scientists believe that La Nina, a hydrological phenomenon, will not have a significant impact on the world climate, but will bring more rainfall to Guangdong, Fujian, Zhejiang and even the entire southeast coast in a certain period of time.

We are in La Nina state this year, that is, the SST in the equatorial eastern Pacific is 0.5 degrees lower than normal, which has a very obvious impact on China's climate. Under the influence of La Nina phenomenon, the meridional circulation in East Asia is abnormal, which is very beneficial to the southward movement of cold air in northern China. It has given us a cold winter, so we can see that this cold winter has already appeared this year.

Rani, that's just one of the reasons. Another reason for the heavy snow is as follows:

Since 2008, the high pressure in Asia has been very active, forming a cold air mass in the south, affecting China and causing large-scale gale and cooling weather. However, due to the active warm air mass in the south this year, a large number of warm and humid air currents from the Pacific Ocean and the Indian Ocean frequently patronize the southern region. When the powerful cold air mass from Mongolia and Siberia quickly moved south to meet the warm and humid air mass, the cold and warm air just merged into one. Affected by these two air currents, there have been more rainy and snowy weather recently, especially in the Yangtze River basin, and the low temperature weather has lasted for a long time. If there is only a strong cold air mass without a large amount of water vapor provided by warm and humid air mass, there will only be strong winds and cool weather in the south; If there is only a large amount of water vapor provided by warm and humid air masses, there will be no disastrous weather at all without the arrival of cold air masses. When both are ready, disaster comes.

At the same time, when China was severely hit by a snowstorm, the temperature in the central United States dropped by 20 degrees Celsius, and snowstorms appeared from time to time (2008+0); Central Asia, which has not snowed for a hundred years, suddenly snowed 10mm, setting a new record for Baghdad 100 (2007+02). In the summer of 2007, western Europe suffered severe floods, and Britain and France suffered huge losses (summer of 2007). Since the beginning of winter, the temperature in the northern edge of Russia has hit a new low, once reaching MINUS 50 degrees Celsius ... La Nina is still not over, and the situation is still grim. ...