Red Cliff is in the middle reaches of the Yangtze River in eastern Asia. In winter, the land cools faster than the ocean, so cold high pressures often form in central Asia, such as the Siberian High. In this way, the northwest wind should prevail in the Chibi area at that time.

However, "Unforeseen circumstances may arise", this is an eternal truth. The atmosphere is an extremely complex whole, and it is not impossible for southeasterly winds to blow in the middle reaches of the Yangtze River in the middle of winter. In summary, there are two possibilities.

1. Since the atmospheric movement is complex and changeable, it is likely that a small low pressure accidentally appeared to the west of the Chibi area. Low pressure in the Northern Hemisphere is a cyclone, with air flowing in counterclockwise. In this way, the southeast wind blows just right in Chibi in the eastern part of the low pressure.

2. It is also possible that a small high pressure appeared east of Red Cliff. The high pressure in the Northern Hemisphere is anticyclonic, with air flowing out clockwise. In this way, the southeasterly wind blows just right in the Chibi area in the western part of the high pressure.

Everyone should also pay attention to these: "It is foggy at night, and the fog on the river is even thicker", "The sky is clear and the breeze is motionless." Due to the heavy fog that appeared at night, the weather was fine and the wind was light the next day. We can roughly determine that this fog is radiation fog. This is because radiation fog mostly appears in the winter half of the year, when the air layer is stable and the wind is weak, and it often indicates that the weather will continue to be fine. Radiation fog mostly occurs in weather controlled by high pressure, so it should be the second possibility.

Conclusion:

According to the above analysis, the passage of the "borrowed" easterly wind should be as follows:

A small high pressure forms to the west of Chibi and gradually moves eastward . When this anticyclone passes through the Chibi area, it will be affected by it, causing heavy fog at night and fine weather during the day. When this anticyclone moves to the east of the Chibi area, southeasterly winds prevail in the Chibi area. The east wind is also "borrowed".

I borrowed this Dongfeng from National Geographic. It is absolutely authoritative. Feel free to use it boldly.