ODM2 Variable Name Controlled Vocabulary ODM2 Working Group A vocabulary for describing the name of Variables. Fluorescence index Fluorescence index for measuring fluorescent dissolved organic matter (FDOM). Ratio of emission intensity at 470nm to intensity at 520nm at excitation 370nm. https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.4319/lo.2001.46.1.0038 Added to support Critical Zone Observatory (CZO) data use cases.