Dr. Clifford Voss is a USGS Emeritus Scientist with the Water Resources Mission Area with over 40 years of project management, implementation, field and research experience in groundwater systems.
Dr. Clifford Voss is a USGS Emeritus Scientist with over 40 years of project management, implementation, field and research experience in groundwater systems. He deals with theoretical, field and practical issues in quantitative hydrogeology including: physics of subsurface fluids, computer model development and application to scientific evaluation of hydrogeologic systems, groundwater resources development and protection, coastal/island groundwater resources, subsurface energy production/storage, subsurface waste isolation, and cold-regions hydrology.
Dr. Voss is recognized as an international expert on groundwater modeling. He consults extensively on groundwater system evaluation and management, and lectures internationally on these and related subjects. The practical methodology and codes that Voss and his colleagues have developed (SUTRA and SutraSuite) are in standard use worldwide in subsurface assessment, aiding in quantity-quality management of groundwater resources and in evaluation of human impacts on the subsurface environment. These codes also allow development of a deeper understanding of important hydrogeologic processes.
His current interests involve: subsurface flow/transport in heterogeneous hydrogeologic media, cold-regions hydrology, development and application of practical methodology and subsurface hydrology simulation codes (SUTRA and SutraSuite) with freeze/thaw for study of ground-ice and permafrost in cold regions and associated code-benchmark development, flow and transport in variable-density subsurface fluids (seawater, brine, hot/cold groundwater), inverse modeling, network design, optimization of groundwater management, use of isotopes in characterizing subsurface systems, and the climate/ecology/society/water nexus.
Dr. Voss has conducted many crucial subsurface resource understanding and management studies, including: nuclear waste repository siting safety and performance (Sweden, Germany, Japan), coastal aquifer and seawater intrusion management (Hawaii USA, other USA, and worldwide), transboundary aquifer management (Nubian Aquifer of Egypt, Libya, Chad, Sudan); sustainability of arsenic-free groundwater supply (Bengal Delta Aquifer of India, Bangladesh); discovering the dynamics of cold-regions hydrologic systems (Canada, China, Greenland/Denmark, Sweden, USA).
Dr. Voss is Executive Editor of "Hydrogeology Journal" the official journal of the International Association of Hydrogeologists (since 1994).
Science and Products
The Impact of Sea-Level Rise and Climate Change on Pacific Ocean Atolls
Characterizing global variability in groundwater arsenic
Birdsall-Dreiss Distinguished Lecturer: Clifford I. Voss
Clifford Voss was selected as the 2015 Birdsall-Dreiss Distinguished Lecturer by the Geological Society of America. Cliff, an internationally recognized expert in groundwater modeling, has over 35 years of project management, implementation, field work and research experience in groundwater systems. Upon request, Cliff will present general-audience lectures on groundwater or ground ice/permafrost.
Hydrologic modeling of a perennial firn aquifer in southeast Greenland
Surface energy balance of sub-Arctic roads with varying snow regimes and properties in permafrost regions
Simulating water and heat transport with freezing and cryosuction in unsaturated soil: Comparing an empirical, semi-empirical and physically-based approach
The firn meltwater Retention Model Intercomparison Project (RetMIP): Evaluation of nine firn models at four weather station sites on the Greenland ice sheet
Wildfire-initiated talik development exceeds current thaw projections: Observations and models from Alaska's continuous permafrost zone
The influence of snow cover, air temperature, and groundwater flow on the active-layer thermal regime of Arctic hillslopes drained by water tracks
Water tracks enhance water flow above permafrost in upland Arctic Alaska hillslopes
SUTRA, a model for saturated-unsaturated, variable-density groundwater flow with solute or energy transport—Documentation of generalized boundary conditions, a modified implementation of specified pressures and concentrations or temperatures, and the lake
Modeling δ18O as an early indicator of regime shift arising from salinity stress in coastal vegetation
Development of perennial thaw zones in boreal hillslopes enhances potential mobilization of permafrost carbon
Preamble, part a: Groundwater quantity of South Asia
Celebrating 50 years of SWIMs (Salt Water Intrusion Meetings)
SutraGUI: Graphical Pre- and Post-Processor for SUTRA
SutraGUI is a graphical environment for setting up and executing 2D and 3D SUTRA runs, and for visualizing results from 2D SUTRA runs. It is compatible with SUTRA Version 2.2 and requires Argus Open Numerical Environments (Argus ONE) commercial software,
SUTRA: A Model for 2D or 3D Saturated-Unsaturated, Variable-Density Ground-Water Flow With Solute or Energy Transport
SutraSuite is a collection of software for groundwater modeling in both two spatial dimensions (2D) and three spatial dimensions (3D). It includes the SUTRA groundwater model, the SutraGUI pre-processor, the SutraPrep text-based preprocessor, and the SutraPolot post-processor.
Science and Products
- Science
The Impact of Sea-Level Rise and Climate Change on Pacific Ocean Atolls
Providing basic understanding and specific information on storm-wave inundation of atoll islands that house Department of Defense installations, and assessing the resulting impact of sea-level rise and storm-wave inundation on infrastructure and freshwater availability under a variety of sea-level rise and climatic scenarios.Characterizing global variability in groundwater arsenic
Groundwater contaminated with naturally occurring arsenic is a widespread problem affecting many alluvial and deltaic aquifer systems throughout the world. The human health toll from consuming groundwater with high levels of arsenic is staggering in its proportions. Furthermore, the use of arsenic contaminated groundwater for irrigation is observed to result in diminished crop yields and thus poseBirdsall-Dreiss Distinguished Lecturer: Clifford I. Voss
Clifford Voss was selected as the 2015 Birdsall-Dreiss Distinguished Lecturer by the Geological Society of America. Cliff, an internationally recognized expert in groundwater modeling, has over 35 years of project management, implementation, field work and research experience in groundwater systems. Upon request, Cliff will present general-audience lectures on groundwater or ground ice/permafrost.
- Publications
Filter Total Items: 71
Hydrologic modeling of a perennial firn aquifer in southeast Greenland
A conceptual model, based on field observations and assumed physics of a perennial firn aquifer near Helheim Glacier (southeast Greenland), is evaluated via steady-state 2-D simulation of liquid water flow and energy transport with phase change. The simulation approach allows natural representation of flow and energy advection and conduction that occur in vertical meltwater recharge through the unAuthorsOlivia Miller, Clifford I. Voss, D. Kip Solomon, Clément Miège, Richard Forster, Nicholas Schmerr, Lynn MontgomerySurface energy balance of sub-Arctic roads with varying snow regimes and properties in permafrost regions
Surface energy balance (SEB) strongly influences the thermal state of permafrost, cryohydrological processes, and infrastructure stability. Road construction and snow accumulation affect the energy balance of underlying permafrost. Herein, we use an experimental road section of the Alaska Highway to develop a SEB model to quantify the surface energy components and ground surface temperature (GST)AuthorsLin Chen, Clifford I. Voss, Daniel Fortier, Jeffrey M. McKenzieSimulating water and heat transport with freezing and cryosuction in unsaturated soil: Comparing an empirical, semi-empirical and physically-based approach
Freezing of unsaturated soil is an important process that influences runoff and infiltration in cold-climate regions. We used a simple numerical model to simulate water and heat transport with phase change in unsaturated soil via three different approaches: empirical, semi-empirical and physically based. We compared the performance and parameterization of each approach through testing on three expAuthorsJoris C Stuurop, Sjoerd E. A. T. M van der Zee, Clifford I. Voss, Helen K FrenchThe firn meltwater Retention Model Intercomparison Project (RetMIP): Evaluation of nine firn models at four weather station sites on the Greenland ice sheet
Perennial snow, or firn, covers 80 % of the Greenland ice sheet and has the capacity to retain surface meltwater, influencing the ice sheet mass balance and contribution to sea-level rise. Multilayer firn models are traditionally used to simulate firn processes and estimate meltwater retention. We present, intercompare and evaluate outputs from nine firn models at four sites that represent the iceAuthorsBaptiste Vandecrux, Ruth Mottram, Peter Langen, Robert Fausto, Martin Olesen, C. Max Stevens, Vincent Verjans, Amber Leeson, Stefan Ligtenberg, Peter Kuipers Munneke, Sergey S. Marchenko, Ward van Pelt, Colin R. Meyer, Sebastian B. Simonsen, Achim Heilig, Samira Samimi, Shawn J. Marshall, Horst Machguth, Michael J. MacFerrin, Masashi Niwano, Olivia L. Miller, Clifford I. Voss, Jason E. BoxWildfire-initiated talik development exceeds current thaw projections: Observations and models from Alaska's continuous permafrost zone
As the Arctic warms and wildfire occurrence increases, talik formation in permafrost regions is projected to expand and affect the cycling of water and carbon. Yet, few unified field and modeling studies have examined this process in detail, particularly in areas of continuous permafrost. We address this gap by presenting multimethod, multiseasonal geophysical measurements of permafrost and liquidAuthorsDavid Rey, Michelle A. Walvoord, Burke J. Minsley, Brian A. Ebel, Clifford I. Voss, Kamini SinghaThe influence of snow cover, air temperature, and groundwater flow on the active-layer thermal regime of Arctic hillslopes drained by water tracks
Permafrost in Arctic watersheds limits soil biological activity to a thin, seasonally thawed active layer that contributes water to streams. In many hillslopes, relatively wet drainage features called water tracks have distinct freeze-thaw patterns that affect groundwater flow and storage, and thus the export of heat and solutes to Arctic streams. This study uses groundwater flow and energy transpAuthorsCaitlin R Rushlow, Audrey H Sawyer, Clifford I. Voss, Sarah E GodseyWater tracks enhance water flow above permafrost in upland Arctic Alaska hillslopes
Upland permafrost regions occupy approximately one third of the Arctic landscape. In upland regions, hydrologic fluxes are influenced by water tracks, curvilinear features on hillslopes that preferentially fill with and route water in response to snowmelt and rainfall when the soil above continuous permafrost thaws in the summer. As continued warming of the Arctic may alter hydrologic cycling leadAuthorsSarah G. Evans, Sarah E Godsey, Caitlin R Rushlow, Clifford I. VossSUTRA, a model for saturated-unsaturated, variable-density groundwater flow with solute or energy transport—Documentation of generalized boundary conditions, a modified implementation of specified pressures and concentrations or temperatures, and the lake
Version 3.0 of the SUTRA groundwater modeling program offers three new capabilities: generalized boundary conditions, a modified implementation of specified pressures and concentrations or temperatures, and lakes. Two new types of “generalized” boundary conditions facilitate simulation of a wide range of hydrologic processes that interact with the groundwater model, such as rivers, drains, and evaAuthorsAlden M. Provost, Clifford I. VossModeling δ18O as an early indicator of regime shift arising from salinity stress in coastal vegetation
In many important coastal habitats, a combination of increasing soil salinization due to sea level rise, reduced precipitation and storm surges may induce regime shift from salinity-intolerant glycophytic vegetation to salinity-tolerant halophytic species. Early detection of regime shift due to salinity stress in vegetation may facilitate conservation efforts. It has been shown that the 18O valueAuthorsSu Yean Teh, Hock Lye Koh, Donald L. DeAngelis, Clifford I. Voss, Leonel da Silveira Lobo SternbergDevelopment of perennial thaw zones in boreal hillslopes enhances potential mobilization of permafrost carbon
Permafrost thaw alters subsurface flow in boreal regions that in turn influences the magnitude, seasonality, and chemical composition of streamflow. Prediction of these changes is challenged by incomplete knowledge of timing, flowpath depth, and amount of groundwater discharge to streams in response to thaw. One important phenomenon that may affect flow and transport through boreal hillslopes is dAuthorsMichelle A. Walvoord, Clifford I. Voss, Brian A. Ebel, Burke J. MinsleyPreamble, part a: Groundwater quantity of South Asia
AuthorsClifford I. VossCelebrating 50 years of SWIMs (Salt Water Intrusion Meetings)
The Salt Water Intrusion Meetings, or SWIMs, are a series of meetings that focus on seawater intrusion in coastal aquifers and other salinisation processes. 2018 marks the 50th year of the SWIM and the 25th biennial meeting. The SWIM proceedings record half a century of research progress on site characterisation, geophysical and geochemical techniques, variable-density flow, modelling, and water mAuthorsVincent E. A. Post, Gualbert Oude Essink, Adam Szymkiewicz, Mark Bakker, Georg Houben, Emilio Custodio, Clifford I. Voss - Software
SutraGUI: Graphical Pre- and Post-Processor for SUTRA
SutraGUI is a graphical environment for setting up and executing 2D and 3D SUTRA runs, and for visualizing results from 2D SUTRA runs. It is compatible with SUTRA Version 2.2 and requires Argus Open Numerical Environments (Argus ONE) commercial software,
SUTRA: A Model for 2D or 3D Saturated-Unsaturated, Variable-Density Ground-Water Flow With Solute or Energy Transport
SutraSuite is a collection of software for groundwater modeling in both two spatial dimensions (2D) and three spatial dimensions (3D). It includes the SUTRA groundwater model, the SutraGUI pre-processor, the SutraPrep text-based preprocessor, and the SutraPolot post-processor.