<P> Petrichor (/ ˈpɛtrɪkɔər /) is the earthy scent produced when rain falls on dry soil . The word is constructed from Greek πέτρα petra, meaning "stone", and ἰχώρ īchōr, the fluid that flows in the veins of the gods in Greek mythology . </P> <P> The term was coined in 1964 by two Australian CSIRO researchers, Isabel Joy Bear and Richard G. Thomas, for an article in the journal Nature . In the article, the authors describe how the smell derives from an oil exuded by certain plants during dry periods, whereupon it is absorbed by clay - based soils and rocks . During rain, the oil is released into the air along with another compound, geosmin, a metabolic by - product of certain actinobacteria, which is emitted by wet soil, producing the distinctive scent; ozone may also be present if there is lightning . In a follow - up paper, Bear and Thomas (1965) showed that the oil retards seed germination and early plant growth . </P>

What is the name of the smell after it rains