I made a movie (about a minute long) of DARM over several hours yesterday with a 100 average exponential decay. It takes a couple of minutes to watch and shows that there are bumps, possibly from scattering, that come and go sometimes independently of each other. I say somewhat, because, when the spectrum gets good all of the bumps seem to be gone. There is also a broad background that rises and falls that does not seem to be composed of bumps.

https://ldas-jobs.ligo-wa.caltech.edu/~robert.schofield/DARM100averageExponential.mov