How did the ancients "know the sky from the clouds" thousands of years ago?

This year, there have been persistent high temperature weather in many areas. Take Shanghai as an example, especially beautiful clouds always appear in the sky at dusk. Through experience, it is found that clouds on hot days are always particularly beautiful. In fact, thousands of years ago, the ancients judged the weather by looking at the shape and color of clouds.

Give the most common example. In summer, we can find that as long as there are convective clouds, there will be thunderstorms. Meteorologists believe that this is because when there is a big difference between the bottom temperature and the top temperature, it will move up and down to form convection. This kind of exercise gradually reduces the warm air until the water vapor condenses. The clouds formed at this time are convective clouds, which will cause thunderstorms. At the same time, the characteristics of this cloud are also obvious. Convective clouds change a lot in a day, and the clouds are fluffy and diverse, especially in the evening.

In fact, the color of clouds can also identify the weather, because sunlight will scatter after entering the atmosphere, and different colors of light will be scattered according to the different solar spectrum. If the sky is clear, the colors will show all kinds of colorful optical fibers, but if it is high temperature, some blue light will be lost in the scattering process, so the remaining light will be particularly red and orange, so the clouds on high temperature days will generally look particularly hot.

In fact, the ancients knew the weather from the clouds thousands of years ago, and there were related records in the Book of Songs, so there were many related proverbs. In the Tang Dynasty, Colleen Chan was the first book to predict the weather based on images, and most of these contents were later supported by meteorology. For example, clouds like fish scales are called cirrocumulus, which is a sign of bad weather. In the Ming dynasty, there was an atlas of the corresponding changes in the sky, which also provided a model for future generations to observe the weather. After the founding of New China, the National Meteorological Observatory also carried out observation of the sky, and made great progress in understanding the weather by looking at clouds.