Tracking down the origins of Advanced LIGO noise: some examples

In order to increase the sensitivity of Advanced LIGO (aLIGO) to astrophysical events, various sources of instrumental and environmental noise must be identified and ameliorated. Here we provide examples of efforts to understand the origin of types of noise manifested as short-duration bursts (glitches) at LIGO Hanford Observatory (LHO). Among several examples of glitch classes found and understood at LHO in aLIGO's second observing run, O2, are glitches caused by airplanes, by an incorrect servo setting, and by thirsty ravens. For each class, the process of relating an observed anomaly in the gravitational wave channel to an instrumental or environmental cause will be described.