The Scent Of Rain: Petrichor

After a heavy cloudburst, it is one of the most pleasing smells that everyone loves. You are not alone if you also think where this sweet, fresh and powerful vivid smell comes from. This smell is usually felt after a pleasant rainfall. The odor was

particularly prevalent in arid regions and was widely recognized and associated with the first rains after a period of drought, also when the humidity is increased we experience such smell.

In an article given by two Australian scientists, a term was coined Petrichor, which actually stands for the aroma coming after rainfall. It was concluded that one of the reasons behind the smell is a blend of some oils secreted by the plants during that time. These oils also combine with other compounds to form this smell, some of the bacterias like actinomycetes (contribute to soil systems) secret geosmin which also produces the aroma.

This particular chemical is secreted by the bacterias when they produce spores and these are sent into the air which is further conveyed to our noses, such bacterias become active in wet conditions only. Ozone also serves as a reason for this smell especially after a thunderstorm as lighting can split the molecules to form oxygen and nitrogen in the atmosphere which further combines to form nitric oxide, so it's evident that we sometimes smell ozone too.