Take a deep breath in… and out. Consider the air you’re breathing.
Ever wonder what’s in it?
Air is composed of a number of gases- the most important of which is oxygen! But the main component of air is not oxygen, but rather nitrogen. In fact nitrogen is four times more abundant than oxygen in the atmosphere, making up 78% of the total volume of air.
We’re quite fine with oxygen concentrations staying at 21% as oxygen is quite combustible. Higher concentrations would lead to a lot more fires while a lower concentration would leave us struggling to catch a breath. Essentially nitrogen is a space filler! In its gas form it doesn’t react to other substances like oxygen does and as such has built up in our atmosphere over millions of years.
Up next, taking up just under 1% of the atmosphere is argon. Argon is an element similar to neon in the same family called the Noble Gases. It doesn’t do much as it is very stable and non-reactive.
Those 3 gases make up nearly 100% with the key word being nearly. One tenth of one percent is not accounted for. The compounds that make up this very small piece of the pie are called “trace gases.” Some are inert like argon, while others are some of the most important chemicals in our atmosphere: greenhouse gases.
These will be covered much more in depth in a future Moment of Science, but understand that while these exist in very small concentrations- they pack a punch. Without them, our planet would be 90 degrees colder and life as we know it wouldn’t exist. Pretty incredible for gases, including carbon dioxide, which are measured in parts per million in a sample of air. Our daily activities increase their concentrations along with other trace gases such as ozone.
Made up of 3 oxygen atoms, ozone is interesting as at the surface it is hazardous to our health as it’s a by-product of pollution but high up in the atmosphere it forms naturally through a chemical reaction and is quite necessary as it blocks harmful UV rays.
And that’s… still not everything as those numbers are for dry air and, as we know here in the Lowcountry, air is anything but dry. Water vapor varies by region but can make up 1-5% of air’s volume, adjusting the other concentrations accordingly.
And now we’re done! Check back next week as we’ll continue to chat about air and discuss an activity that requires considering that gas that mainly takes up space: nitrogen!
Storm Team 2 Meteorologist David Dickson