The smell after rain is pleasant to absolutely most people, but few people know that this specific scent has its own name – petricor.
The term “petricor” was coined during a study of this odor in 1964 by scientists Roderick Thomas and Isabella Bear. The word “petricor” has Greek roots: “petra” means “stone” and “chor” means water.
So what causes the pleasant fragrance that occurs when rain falls on the ground? During the dry season, plants constantly release all sorts of oils that are absorbed into the earth and rocks. When it rains on the ground, the water gets into the microcracks and pores. The air in them forms bubbles on the wet surface, which, when they burst, release many microdroplets into the air. These tiny particles, which contain vegetable oils, are picked up by the air currents and carried around, creating that unique and beloved scent.
For the same reason, by the way, when it rains, there are a huge number of soil bacteria in the air. Scientists have found that rains can therefore pose a danger to immune-compromised people.