Petrichor is the distinct and pleasant smell that emerges during the first rainfall after a prolonged dry period. This unique aroma is a result of several natural components, including oils released by plants, soil bacteria, and a specific molecule known as geosmin. Geosmin is produced by certain soil-dwelling bacteria and is responsible for the earthy scent often associated with fresh rain.
The human nose is remarkably sensitive to geosmin, capable of detecting it at extremely low concentrations, which contributes to the strong perception of petrichor. This phenomenon not only evokes nostalgic feelings for many but also plays a significant role in the ecosystem, signaling the arrival of moisture which can impact plant growth and animal behavior.
Source: news.google.com