ODM2 Variable Name Controlled Vocabulary ODM2 Working Group A vocabulary for describing the name of Variables. Europium Europium is a chemical element with symbol Eu and atomic number 63. It was isolated in 1901 and is named after the continent of Europe. It is a moderately hard, silvery metal which readily oxidizes in air and water. Wikipedia https://en.wikipedia.org/wiki/Europium Added to support Critical Zone Observatory (CZO) data use cases.