How advances in spectroscopy may change climate science
When you look at the spectrum of sunlight, you see a broad rainbow of colours over which are superimposed many fine dark bands. These correspond with the particular wavelengths of light that are absorbed when electrons transition from one energy level to another within the atoms and molecules of the sun’s atmosphere. The fact that these lines are quite sharp is actually one of the easiest ways to verify that we do indeed live in a quantum universe, in which an atom’s electrons are only allowed to occupy certain energy levels and not those in between.
Information gathered from this kind of spectroscopy has been of enormous importance in understanding both the fundamental structure of matter and how chemical reactions work at a nuts and bolts level. However, in spite of its usefulness, absorption spectroscopy does have its limitations. It’s especially hard to do on very diffuse and lightly absorbing materials such as the low pressure gasses of relevance to atmospheric physics.