In September, the shoes will be released for the new school year Pens, pencils and erasers. The excitement of a debut is mixed with the fear of beginners, a feeling that has been with me since childhood. Until you’ve walked a distance, you don’t know if your new shoes will cause friction or liven up your walking. Even though many years ago my schedule started in January rather than September, this taste of a new phase fills the air and makes my hair frizz. AndIn September it rains when it is hot, there are more aerosols floating around, and it smells like autumn and summer, and it smells like ozone, dimethyl sulfide, geosmin, and petrichor. These molecules tangle the mane, which is still a symptom of tangled thoughts as well. These are molecules that move from the air to the ground until they sink into the nose, which is the shortest path to memory.
The scent that announces rain is metallic. It smells like electricity. The main molecule responsible is ozone, a gas made up of three oxygen atoms instead of the two that make up the oxygen we breathe. Stormy lightning breaks diatomic oxygen in two, leaving the loose atoms eager to find a mate. These loose atoms, once they find an oxygen molecule, bond to it, Converting a stable dimer into an aromatic ternary.
When there is a storm, ozone is formed in the troposphere. However, not all storms accompanied by lightning and thunder can be seen and heard. There are storms that occur in the clouds 5 kilometers above our heads. Cumulus storm clouds are composed of small ice crystals arranged in a density gradient: lighter ones at the top and heavier ones at the bottom. Lighter crystals usually have a positive electrical charge, while heavier crystals have a negative charge. This potential difference causes lightning strikes. Some of them reach the positively charged Earth at a rate of 100 beams per second.
When it starts raining it smells Wet ground. This description is also the etymological origin of the word geosmin. Geosmin is an alcohol-type compound. In reality, There are people who are reminded of ethyl alcohol. However, geosmin has a complex chemical structure It makes it more visible to our olfactory receptors. If there’s a geosmin molecule floating among 200,000 air molecules, we notice it. It’s part of the olfactory language of species evolution: camels are particularly sensitive animals to this compound, so geosmin traces its way to water in the air.
Geosmin is produced by bacteria, Streptomyces colicorwhich in Wetting with rainwater stimulates your metabolism. In the countryside, where the smell of rain is deeper, there are fungi and cyanobacteria that also produce small amounts of geosmin. However, in cities geosmin decomposes due to environmental acidity, where the air is more laden with sulfur, nitrogen and carbon oxides.
After rain the scent becomes floral and rinses off. It’s Petrichor. The composition of this scent It was described in 1964 in a scientific article. The researchers collected water vapor emanating from the rocks after rainfall and distilled it to obtain aromatic compounds. They found that a group of volatile oils resulted in a trace of perfume left by the rain.
Investigations into September odors are ongoing. one of The latest and most influential scientific studies It was published by MIT in 2015. These scientists studied how aerosols form when rain hits the ground. Until then, it was thought that most aerosols in the air came from sea spray, from waves crashing onto the coast, which is why in coastal areas where the sea is rougher, it smells very much like the sea. The main aromatic compound of Marine aerosol is dimethyl sulfide. It also contains salts such as chlorides that are perceived by the tongue, causing us to confuse taste with smell. The researchers found that in addition to marine aerosols, which are floating particles on the order of micrometers, rain also produces aerosols of different sizes and compositions depending on the type and porosity of the impact surface. They studied the aerosols produced by droplets after they hit asphalt, pavement, or the ground. Depending on the soil When the rain gets wet, various scented aerosols will rise.
September scent map drawn by chemical trace. It smells a little different in every landscape. This combination of rain and heat subtly soaks the air and earth, simultaneously emitting a scent of omen and nostalgia. These molecules nest in the nose and quickly travel to the brain The substance from which roots are made.