As any science or science fiction nerd knows, lasers are cool. Really cool. They can be used for medical applications, welding, printing, cutting, and communications, among other things. One of those other things is blasting gases and materials with electromagnetic radiation and using the visual results to see what they’re made of, known as spectroscopy.
Spectroscopy has come a long way since our pal Isaac Newton was playing around with prisms and discovered white light could be split up into a bunch of colors by passing through one (unknowingly inspiring Pink Floyd’s Dark Side of the Moon cover art a couple of centuries into the future). Now we no longer rely on prisms alone, but systems equipped with state of the art tech to extract as much information as possible from experiments. These experiments aren’t always confined to a lab - sometimes they involve flying around in an airplane shooting lasers into the atmosphere, like a recent experiment conducted by NASA.
Shooting lasers into the atmosphere isn’t just for fun and games - the folks at NASA were measuring carbon dioxide and water vapor, two potent greenhouse gases. The system is loosely based on the principles of - you guessed it - spectroscopy, but with an added component of being able to use the laser to determine not just what the gases are, but where in the atmosphere they are. Similar systems, called LIDAR systems, have been used recently in comparable experiments worldwide to measure the prevalence of localized greenhouse gases, including one in France. Using LIDAR systems for atmospheric spectroscopy is a new way to understand what’s going on in our atmosphere.
With the rise of global issues like climate change, environmental monitoring is becoming super important to determine exactly what is changing, how fast the changes are occurring, and what’s causing the change. The experiments shine a light - literally - on the scope of the problem, and using laser systems for atmospheric spectroscopy, accurate climate models can be created and the effects on the local environment can be studied.
