How does Qinling stop the cold air going south?

How does Qinling stop the cold air going south? First of all, the high altitude of the Qinling Mountains has a certain blocking effect on the cold air in the south and the warm and humid air in the north, but at the same time, the long journey of cold air from west to east and over mountains and mountains also consumes its "vitality". In the Qinling Mountains, the cold air will consume more to climb the hill, so the cold air with insufficient intensity will have no "staying power" to "walk" here. Even if there is cold air with strong "endurance", the intensity is obviously weakened after struggling over the mountain, thus causing the phenomenon that the Qinling Mountains "block" the cold air. However, not all cold air can be blocked by the Qinling Mountains. When strong cold air strikes, it can still "break through" the past and affect South China.