OP-ED Rain, Rain, Rain

Rain, Rain, Rain

Written by: Hanna Kamperman

Photo by Hannah Domsic on Unsplash

Autumn is making a comeback, and while it does mean Summer is over, along with its warm, sunny weather and days on the beach, it also means an end to the heat waves, and the start of the rainy season (finally!). While most of the dutch population is probably more than ready for it to be sunny again, I would say most people can agree that sitting inside your warm house while it is raining outside and being able to open your window to smell it the next morning is one of the best feelings ever. But why do we love it so much? What’s the appeal of rain, and why does it smell so good? I’ve done some exploring into these questions, so keep reading to see what I found. First of all though, a little disclaimer. Knowing the name of the smell of rain and where it comes from could make the nostalgia of it and the memories that it pulls up a bit less strong. This might sound strange, but there was a study done at the University of Stockholm. There were three groups of people, each presented with a different situation. One group was just exposed to a scent, the second group to the name of the scent without the actual smell, and the third group with both. The first group had a much stronger emotional response than the other two. So, knowing what the smell is could interfere with how your brain calls up memories triggered by it. So if you want to know, do so at your own risk. (It’s really not that big of a deal – rain still smells great to me – but I just wanted to be a little dramatic, you know?) What many of you probably already know is that that after-therain smell is called petrichor. If you didn’t know that, well, you know now! It was given the name by two Australian scientists who discovered the origins of petrichor back in the 60s. It is derived from two Greek words; petros, meaning ‘stone,’ and ichor, the word for ‘the fluid that flows in the veins of the gods’ (dramatic, I know). The smell is produced by bacteria. The bacteria are a specific type of bacteria called actinobacteria which break down dead things. They produce a lot of chemicals through this 11

process, and one of them is called geosmin, a type of alcohol that humans are really sensitive to - we can smell it in really small quantities, down to a couple of parts per trillion air molecules. The moist environment created by rain activates these bacteria’s processes. The reason we can smell this so well after it has rained is that when raindrops hit the earth, they splatter and trap little particles in air bubbles, and you guessed it, geosmin is among those little particles. This way they can be carried in the wind, allowing us to smell them. If it’s raining hard, the smell can be strong enough/the wind can blow far enough that the smell can be carried farther away, explaining why you can oftentimes smell a shower coming. Why we like the smell of rain, in a psychological sense, was harder to find information on, which is why this part will be a bit more hypothetical. The rain itself is nice and soothing for a multitude of reasons. First of all, it’s refreshing and clears the air of pollutants, and makes it smell good. Secondly, when it’s raining the air pressure is lower and there’s a lot of water vapor in the air, which together lower the overall oxygen levels. This makes your brain more tired and thus sleepier. Third of all, lightning and the friction between the rain and the air cause there to be a lot of negative ions, which are overall good for your nervous, respiratory, and cardiovascular systems and relax you. Another thing is that when it rains or the weather is stormy, it is usually darker as well. This causes your body to produce more melatonin - the hormone that makes you feel tired and sleepy. Finally, the sound of rain is rhythmic and quiet, and it’s also white noise which masks other loud sounds that stimulate your brain. There are so many things that make rain so relaxing that I think the smell of rain is also relaxing by association because it brings back those memories of soothing times. That’s just what I think, and there’s probably a much deeper reason that nobody knows about yet, because why else would poets and perfume companies and such be so obsessed with it? I think that’s it for this rain-centric research for now, so I say go out and enjoy that rain – that petrichor – and hope that it at least does not pour down on you on the way to school tomorrow. Happy fall!

Photo by Tīna Sāra on Unsplash