Why does the southeast wind blow in the cold winter in Battle of Red Cliffs?

Chibi is in the middle reaches of the Yangtze River in East Asia. In winter, the land cools faster than the ocean, so cold high pressure, such as Siberian high pressure, often forms in Central Asia. In this way, the northwest wind should prevail in Chibi area at that time.

However, it is an eternal truth that "the weather is unpredictable". The atmosphere is an extremely complex whole, and it is not impossible to blow southeast winds in the middle reaches of the Yangtze River in the middle of winter. In summary, there are two possibilities.

1. Due to the complex and changeable atmospheric movement, it is likely that a small depression will occasionally appear in the west of Chibi area. The low pressure in the northern hemisphere is a cyclone, and the airflow flows counterclockwise. In this way, the southeast wind just blows to Chibi in the east of the low pressure.

2. It is also possible that there is a small high pressure east of Chibi. The high pressure in the northern hemisphere is an anticyclone, and the airflow flows clockwise. In this way, the southeast wind just blows in the Chibi area in the west of the high pressure.

We should also pay attention to these: "There is fog at night, and the fog on the river is thicker" and "Wan Li is clear and the breeze is quiet". Because there is fog at night, the weather is fine and the wind is light the next day, so it can be roughly judged that the fog is radiation fog. This is because most of the radiation fog appears in the winter half year, and the air layer is stable and the wind is weak, which often indicates that the weather will continue to be fine. Radiation fog is mostly produced in high-pressure weather control, so it should be the second possibility.

Conclusion:

According to the above analysis, the process of "borrowing" Dongfeng should be like this:

A small high pressure formed in the west of Chibi and gradually moved eastward. When this anticyclone passes through Chibi area, Chibi area is affected by it, which is foggy at night and sunny during the day. When this anticyclone moves to the east of Chibi area,