Analyses on the 500 hPa circulation of the extreme cold winter indicates that it would be the extreme cold winter in Hainan island when the polar vortex lied on the shore of Arctic Ocean of the eastern Siberian.

• 通过对海南岛异常特冷年500hPa环流场分析表明，海南岛异常特冷年主要发生在东西伯利亚极涡南落的年份里