The rainy season is here. Rainy season can be quite a hassle for some people, but could also be the awaited moment for others. A few of us would fall in love with the smell of rain.
The smell of rain after a long time not raining can give us slight happiness. It is not a weird thing to fall in love with it. The smell comes from natural reactions of bacteria, plant oil, and lightning. Thanks to the chemistry that triggers joy in us.
The pleasant smell of rain is known as petrichor. When the rain reaches the ground, some specific chemicals will release the good smell.
The raindrops trap air bubbles that contain geosmin, a molecule secreted by soil-dwelling bacteria. When the raindrops hit the soil, it will release as aerosols which dispersed through the air. The human nose can be really sensitive to smell it when it is dispersed to the air.
According to Australian researchers, Isabel Joy Bear and R. G. Thomas, some plants secrete oils in hot conditions. The oils will be released into the air when it rains the same way as geosmin.
The strong smell of rain also comes from the splitting of oxygen and nitrogen from lightning. They will recombine to form a nitric oxide which has a pungent, chlorine-like odor.