Differential optical absorption spectroscopy
Have you ever seen a "Where's Waldo" book? It's like finding Waldo in a big group of people. That's what scientists do when they want to study the air around us: they look for certain molecules (or "Waldos") in the air. But how can they find them? They use a special technique called differential optical absorption spectroscopy, or DOAS for short.
First, they shine a special light (like a flashlight) on the air. The light is made up of different colors, just like a rainbow. When the light hits the air, some of it gets absorbed by the molecules in the air. This is like the molecules eating the colors of the rainbow. Different molecules eat different colors, so scientists can tell which molecules are in the air by which colors are missing.
But wait, what does "differential" mean? Well, the scientists don't just shine the light on the air once - they shine it on the air in two different ways, and then compare the two. It's like taking two "Where's Waldo" books and comparing them to see if Waldo moved. Instead of looking for Waldo, they're looking for the missing colors. By comparing the two times they shone the light, they can figure out how much of the molecule is in the air and where it is.
DOAS is a very important tool for scientists who study the air. It helps them figure out what's in our air, how much of it there is, and where it is coming from. It's kind of like a game of "Where's Waldo," but with much more important things than a little guy in a red and white striped shirt.
First, they shine a special light (like a flashlight) on the air. The light is made up of different colors, just like a rainbow. When the light hits the air, some of it gets absorbed by the molecules in the air. This is like the molecules eating the colors of the rainbow. Different molecules eat different colors, so scientists can tell which molecules are in the air by which colors are missing.
But wait, what does "differential" mean? Well, the scientists don't just shine the light on the air once - they shine it on the air in two different ways, and then compare the two. It's like taking two "Where's Waldo" books and comparing them to see if Waldo moved. Instead of looking for Waldo, they're looking for the missing colors. By comparing the two times they shone the light, they can figure out how much of the molecule is in the air and where it is.
DOAS is a very important tool for scientists who study the air. It helps them figure out what's in our air, how much of it there is, and where it is coming from. It's kind of like a game of "Where's Waldo," but with much more important things than a little guy in a red and white striped shirt.