A masterfully painted sunset can be more than just great art. It also holds valuable information about what Earth’s atmosphere was like hundreds of years ago. A group of Greek scientists has determined that studying the colors of sunsets in famous paintings by the likes of Edgar Degas, Caspar David Friedrich and more can help determine the amount of aerosols in the atmosphere at the time the art was created.
In a new study, researchers looked at 554 paintings created between the year 1500 and 2000 and compared the amounts of green and red near the horizon in the artwork to when volcanic eruptions are known to have occurred. Redder sunsets appear when the air is polluted by volcanic ash. They can also happen if the air is filled with dust or man-made aerosols, like sulfate generated from burning fossil fuels.
The study found that the color of the sunsets tended to match up with the historic record of when volcanic ash would have been polluting the air, regardless of the school of painting. To test further, the scientists asked a contemporary painter, Panayiotis Tetsis, to paint a few sunsets over the Greek island of Hydra. Unbeknownst to the artist, a Saharan dust cloud was passing over the island. Lo and behold, his paintings contained high "aerosol optical depth," a measurement of how thick the air is with aerosol particles.
So the art of painting a great sunset is valuable not only from an aesthetic standpoint, but from a scientific one. Data gathered from painted sunsets could be used in climate modeling, when more direct measurements aren’t available.