AUTHOR=Schilling Oliver S. , Halloran Landon J. S. , Delottier Hugo , Sano Yuji , Therrien Rene TITLE=Editorial: Advances and emerging methods in tracer hydrogeology JOURNAL=Frontiers in Water VOLUME=5 YEAR=2023 URL=https://www.frontiersin.org/journals/water/articles/10.3389/frwa.2023.1243114 DOI=10.3389/frwa.2023.1243114 ISSN=2624-9375