Odd O'blography

Petrichor

We're having a spell of hot, dry weather in the Pacific Northwest with temperatures in the nineties (yeah, I know, but it's hot for us). And, after weeks without our typical drizzle, the local paper is predicting a possibility of petrichor later this week. I hadn't seen the word before, so I had to look it up. It's the delightful smell that rises up for a few minutes when raindrops stir up heat-baked dust.

Who doesn't enjoy the scent of fresh rain on parched ground? We have instinctive reactions of relief and even joy when the earthy aroma reminds us that there's life after drought. This weather phenomenon is as old as vegetation itself and has been present throughout the entirety of human history. We may be genetically programmed to appreciate the smell.

The distinctive odor was described by T. L. Phipson in 1891. He theorized that it came from essential oils exuded by plants during dry weather. The oils are absorbed by soil particles and are then aerosolized by falling raindrops. The word petrichor was coined in 1964 by Australian chemists Isabel Joy Bear and Richard Grenfell Thomas who corroborated Phipson's observations.

Petrichor is a combination of the Greek words petra (rock) and ichor (blood of the gods). What an elegant and apt word for a beautiful phenomenon!