Paintings from J.M.W. Turner and other artists are being used to track how pollution levels may have changed over time. Investigators are examining what vivid sunrises and sunsets painted by artists could tell us about the environmental effects of volcanic eruptions.

William Turner was born in England in 1775, and lived until 1851. He is best known as a landscape artist, including a wide variety of sunset paintings. The Lake, Petworth sunset, fighting bucks by the artist is one of the paintings investigators examined to clues to ancient eruptions. 

In 1815, the Tambora Volcano in Indonesia erupted, spewing thousands of tons of debris into the air. Much of this material traveled around the road, making sunsets and sunrises redder and more dramatic. 

Christos Zerefos, from the Academy of Athens in Greece, led the investigation. 

"Nature speaks to the hearts and souls of great artists. But we have found that, when coloring sunsets, it is the way their brains perceive greens and reds that contains important environmental information," Zerefos told the press.  

Researchers studied 554 paintings of sunsets created between 1500 and 2000. A total of 181 artists created the art works, including Rembrandt, Hogarth, Gainsborough, and Rubens. 

"We found that red-to-green ratios measured in the sunsets of paintings by great masters correlate well with the amount of volcanic aerosols in the atmosphere, regardless of the painters and of the school of painting," Zerefos explained. 

Greater than normal levels of red predominated in areas affected by volcanic ash, study says. This allows a way of measuring the aerosol optical depth, a total of all the dust, ash and other particulate matter in the atmosphere at a given time. 

As part of the experiment, Zerefos and his team asked an artist to paint sunsets from a pair of photographs. The photos were of sunsets seen from Hydra Island, located in the Aegean Sea, before and after the passage of a dust cloud from the Sahara. The artist had no knowledge of the dust experiment, but his results matched historic artists. 

When the Tambora eruption occurred on April 10, 1815, it killed 10,000 people instantly, and the blast was heard 800 miles away. An additional 60,000 people perished in a "volcanic winter" that followed. Crops and farm animals died in large numbers, and 1816 became known as the "Year without a Summer." Snow fell in June in New England and Eastern Canada. 

By understanding the way natural phenomenon may have changed temperatures in the past, researchers may be able to gain a better understanding of modern climate change. As dust and ash from the volcanic eruptions scattered light, it also cooled the world. 

Investigation of possible evidence of climate changes shown in paintings was profiled [pdf] in the journal Atmospheric Chemistry and Physics.