The Low Frequency Edge Oscillation in Alcator C-Mod and ASDEX Upgrade I-Modehttps://doi.org/10.7910/DVN/UZUY8BW. McCarthy, A. E. Hubbard, J. Terry, B. Labombard, A. Kuang, R. Bielajew, I. Hutchinson, J. W. Hughes, D. Silvagni, T. Happel, L. Gil, The Alcator C-Mod Team, The Asdex Upgrade TeamHarvard Dataverse2025-03-052025-03-05T20:40:52ZThe Low Frequency Edge Oscillation (LFEO) is a low frequency fluctuation in many plasma quantities in the pedestal region of the I-Mode confinement regime. It is observed on Alcator C-Mod between 10-30kHz and on ASDEX Upgrade between 5-10kHz. On both tokamaks it has been previously identified as a Geodesic Acoustic Mode (GAM), however the recent discovery of the Edge Temperature Ring Oscillation (ETRO) in a similar frequency and spatial location as the LFEO in I-Modes on EAST has called this identification into question. In this paper we investigate the LFEO on C-Mod and AUG using a variety of different experimental techniques including spectral analysis, magnetic mode number analysis, localization, and direct measurement of the LFEO zonal structure and propagation using a Mirror Langmuir Probe. This investigation has reconfirmed the identification of the LFEO as a GAM and determined that it has several key differences from the ETRO.PhysicsAUGC-Modgeodesic acoustic modeI-modeMirror Langmuir Probetokamak2025-03-05CC0 1.0