The Smell of Autumn
Autumn has arrived with its signature sensory inputs. The crunch of leaves underfoot, the kaleidoscope of changing colors, and the distinct scents of fall. In an 1841 letter, English poet and novelist George Eliot called the smell of fall “a perfect anodyne to the restless spirit.” According to Theresa M. Crimmins, PhD (director of the USA National Phenology Network) , autumn’s classic aroma derives mainly from decaying plant material. As leaf fall decomposes, “sugars and carbohydrates break down, emitting volatile organic compounds and other gasses that have a musky, somewhat sweet smell.” There is a regional variation in the odor, dependent on the local plants that drop leaves. With less humidity and lower temperatures, there is a “crisp, clean feeling” attributed to fall air. “Cooler air holds fewer molecules, meaning fewer things are floating around for our noses to detect — the air is less ‘cluttered’ than during warmer, more humid seasons,” Dr. Crimmins sa...