Especially when just coming indoors from the cold outdoors, you can even smell a certain odor on your clothes.
Odor molecules move slowly in low temperatures#
Gas molecules themselves do not have an odor, it is the brain that creates the odor. For ease of understanding, they are collectively referred to as odor molecules.
The molecules spread through random motion, and the higher the temperature, the more active the molecular motion.
A simple example in daily life: when you take leftovers from the refrigerator, you need to get close to smell the odor, but if you put it in the microwave and turn it a few times, then open the microwave, the aroma will fill the entire room.
Different odors affect human perception of food#
Dr. Pamela Dalton from the Monell Chemical Senses Center in Philadelphia: "There are hundreds of different compounds in a cup of coffee. If it's cold, only a small fraction of them can be smelled by the nose, so the overall taste balance will be different."
When you smell a cup of cold coffee, you can get the same taste as hot coffee. But because there are fewer aromatic compounds, it will be much weaker.
Decreased olfactory ability#
As a protective response to cold and dry air, the olfactory ability in our noses will decrease.
Another reason for the special odor of cold air is that our noses are more suitable for warm environments.
When our respiratory system inhales dry, cold air, it quickly raises it to body temperature and humidifies it, otherwise it would damage our lungs. At this time, olfaction and other functions may take a back seat.
Rainwater#
As mentioned earlier, the olfactory ability is most sensitive when the air is humidified and heated, which only happens in summer. Unlike winter, the special odor in summer is usually due to more rainwater.
"Molecules will deposit on the surface of rainwater. If you observe carefully, you will also find that animals often sniff around after rain."
Perhaps because the sense of smell is more acute in summer, there are obviously more songs about the "smell of summer" than in winter.
Not everything brought by a sensitive sense of smell is as beautiful as it is sung in songs: passing by a smelly garbage bin while shopping in summer, the foul smell from the sewer cover.
Olfaction becomes sensation#
Cold air can also trigger the trigeminal nerve, turning the olfactory experience into a sensation.
Anything that enters our nose, we tend to describe it as an odor, even though it is actually a combination of odor and sensation. So when people say they like cold air, they may actually be reacting to the sensation of cold air rather than the actual odor.
The reason why people like cold air and its odor is actually a combination, not only the odor, but also its sensation. Take a deep breath, just like inhaling cool oil into the body.
I feel like it smells like the scent after rain in summer?#
I also feel that the air in winter smells like the low concentration of ozone brought by the rain after summer, but I haven't found any valid information to prove this point yet. So sad.