
Ate Visser
Staff Scientist/Research Scientist, Isotope Hydrology
PLS / Nacsd / Nuclear & Chemical Science Division

Staff Scientist/Research Scientist, Isotope Hydrology
PLS / Nacsd / Nuclear & Chemical Science Division
My research is focused on understanding the sustainability of water resources (both availability and quality) in the context of climate change adaptation and resilience. In my research I combine advanced isotopic tracers with numerical models to provide new perspectives to research questions in terrestrial hydrology and biogeochemistry.
My expertise is understanding reactive transport along groundwater flow paths in relation to groundwater ages and understanding the dynamic behavior of watersheds to rapidly mobilize older water from subsurface storage into streamflow. These aspects of the terrestrial hydro-bio-geo-chemical cycle have important implications for surface water quality and riverine exports of nutrients to coastal ecosystems.
My group at LLNL has developed new capabilities for utilizing isotopic tracers in hydrological research and applied these tracers to urgent water resource questions in California. Building on the unique facilities of the Nuclear and Chemical Sciences Division, we can use a suite of isotopes to investigate sources, pathways, and travel times of water. Our suite of naturally occurring isotopic tracers includes sulfur-35 (87 day half-live), sodium-22 (2.6 year half-life), tritium (12.3 year half-life), tritium-helium groundwater dating, dissolved noble gas analyses for reconstructing recharge conditions, and stable isotope analyses of water and nitrate for identifying water sources and understanding nitrogen cycling in soils and groundwater.
I received my PhD from Utrecht University (The Netherlands) in 2009 for demonstrating trends in groundwater quality in relation to groundwater age and modeling reactive solute transport in groundwater at the groundwater basin scale. After one year at the Netherlands Geological Survey and the research institute Deltares, I joined LLNL as a postdoc in 2010. I now manage the environmental Noble Gas Mass Spectrometry laboratory in the Nuclear and Chemical Sciences Division.
Google scholar: https://scholar.google.com/citations?user=S7EqtdMAAAAJ
Publons: https://publons.com/researcher/2712445/ate-visser/
More information about water science and isotope hydrology at LLNL