Truly the bring the first raining the smell come out everytime when the rain have with the dry soil, I do notice that as well.
But I don't know why it do smell like, but with this I think you have make you to understand something about the smell.
And what is called petrichor, is bacteria is streptomyces
bacteria,it produce geosmin molecule.
Thank for your post I learn from it and it good to always notice and know the meaning.
Thank you for correction.
I still learn so much from what I post today, so the other people who come into my post, I hope they really care about what I missed.