我国进入拉尼娜状态，今年冬天到底是冷还是热？

Group 1 - The core point of the article is that China has entered a La Niña state as of October 2023, which may have significant impacts on the climate and weather patterns in the region [1][3][6] - La Niña is characterized by a significant cooling of sea surface temperatures in the central and eastern Pacific Ocean, with the NINO 3.4 index dropping below -0.5 degrees Celsius [3][4] - The occurrence of La Niña is not equivalent to a La Niña event; a La Niña event is defined by the NINO 3.4 index remaining below -0.5 degrees Celsius for five consecutive months [3][5] Group 2 - La Niña phenomena typically occur every two to seven years, but their frequency has increased in recent years, which is closely related to the complexities of global warming [4] - The current La Niña state may lead to reduced precipitation in southern China during the winter, with a higher probability of drought conditions in the winter and spring [6][7] - The article notes that while La Niña can influence winter temperatures, it is not the sole determinant, as other factors such as Arctic sea ice and atmospheric circulation also play significant roles [6][7]