Christopher T Green, Ph.D.
Christopher Green is a Research Hydrologist with the USGS Water Resources Mission Area.
Research Interests
- Flow and reactive transport in complex geological media
- Nitrogen cycling and fluxes in groundwater in agricultural areas
- Flow and solute transport in the unsaturated zone
- Gas transport in the unsaturated zone
- Effects of biofuels crops on groundwater quality
Science and Products
Filter Total Items: 52
Peclet number as affected by molecular diffusion controls transient anomalous transport in alluvial aquifer-aquitard complexes Peclet number as affected by molecular diffusion controls transient anomalous transport in alluvial aquifer-aquitard complexes
This study evaluates the role of the Peclet number as affected by molecular diffusion in transient anomalous transport, which is one of the major knowledge gaps in anomalous transport, by combining Monte Carlo simulations and stochastic model analysis. Two alluvial settings containing either short- or long-connected hydrofacies are generated and used as media for flow and transport...
Authors
Yong Zhang, Christopher T. Green, Geoffrey R. Tick
Multimodel analysis of anisotropic diffusive tracer-gas transport in a deep arid unsaturated zone Multimodel analysis of anisotropic diffusive tracer-gas transport in a deep arid unsaturated zone
Gas transport in the unsaturated zone affects contaminant flux and remediation, interpretation of groundwater travel times from atmospheric tracers, and mass budgets of environmentally important gases. Although unsaturated zone transport of gases is commonly treated as dominated by diffusion, the characteristics of transport in deep layered sediments remain uncertain. In this study, we...
Authors
Christopher T. Green, Michelle Ann Walvoord, Brian J. Andraski, Robert G. Striegl, David A. Stonestrom
The effects of numerical-model complexity and observation type on estimated porosity values The effects of numerical-model complexity and observation type on estimated porosity values
The relative merits of model complexity and types of observations employed in model calibration are compared. An existing groundwater flow model coupled with an advective transport simulation of the Salt Lake Valley, Utah (USA), is adapted for advective transport, and effective porosity is adjusted until simulated tritium concentrations match concentrations in samples from wells. Two...
Authors
Jeffrey Starn, Amvrossios C. Bagtzoglou, Christopher T. Green
Proper handling of animal tissues from the field to the laboratory supports reliable biomarker endpoints Proper handling of animal tissues from the field to the laboratory supports reliable biomarker endpoints
In the endeavor to assess potential effects to the Gulf of Mexico ecosystem from the Mississippi Canyon 252 incident, referred to as the Deepwater Horizon oil spill, various environmental data have been collected. Whereas initial efforts have included satellite tracking and sediment and water sampling to estimate the geographical scope of oiling, research on biological samples can...
Authors
Heather M. Olivier, Jill A. Jenkins
Simulating water-quality trends in public-supply wells in transient flow systems Simulating water-quality trends in public-supply wells in transient flow systems
Models need not be complex to be useful. An existing groundwater-flow model of Salt Lake Valley, Utah, was adapted for use with convolution-based advective particle tracking to explain broad spatial trends in dissolved solids. This model supports the hypothesis that water produced from wells is increasingly younger with higher proportions of surface sources as pumping changes in the...
Authors
J. Jeffrey Starn, Christopher T. Green, Stephen R. Hinkle, Amvrossios C. Bagtzoglou, Bernard J. Stolp
Accuracy of travel time distribution (TTD) models as affected by TTD complexity, observation errors, and model and tracer selection Accuracy of travel time distribution (TTD) models as affected by TTD complexity, observation errors, and model and tracer selection
Analytical models of the travel time distribution (TTD) from a source area to a sample location are often used to estimate groundwater ages and solute concentration trends. The accuracies of these models are not well known for geologically complex aquifers. In this study, synthetic datasets were used to quantify the accuracy of four analytical TTD models as affected by TTD complexity...
Authors
Christopher T. Green, Yong Zhang, Bryant C. Jurgens, J. Jeffrey Starn, Matthew K. Landon
Science and Products
Filter Total Items: 52
Peclet number as affected by molecular diffusion controls transient anomalous transport in alluvial aquifer-aquitard complexes Peclet number as affected by molecular diffusion controls transient anomalous transport in alluvial aquifer-aquitard complexes
This study evaluates the role of the Peclet number as affected by molecular diffusion in transient anomalous transport, which is one of the major knowledge gaps in anomalous transport, by combining Monte Carlo simulations and stochastic model analysis. Two alluvial settings containing either short- or long-connected hydrofacies are generated and used as media for flow and transport...
Authors
Yong Zhang, Christopher T. Green, Geoffrey R. Tick
Multimodel analysis of anisotropic diffusive tracer-gas transport in a deep arid unsaturated zone Multimodel analysis of anisotropic diffusive tracer-gas transport in a deep arid unsaturated zone
Gas transport in the unsaturated zone affects contaminant flux and remediation, interpretation of groundwater travel times from atmospheric tracers, and mass budgets of environmentally important gases. Although unsaturated zone transport of gases is commonly treated as dominated by diffusion, the characteristics of transport in deep layered sediments remain uncertain. In this study, we...
Authors
Christopher T. Green, Michelle Ann Walvoord, Brian J. Andraski, Robert G. Striegl, David A. Stonestrom
The effects of numerical-model complexity and observation type on estimated porosity values The effects of numerical-model complexity and observation type on estimated porosity values
The relative merits of model complexity and types of observations employed in model calibration are compared. An existing groundwater flow model coupled with an advective transport simulation of the Salt Lake Valley, Utah (USA), is adapted for advective transport, and effective porosity is adjusted until simulated tritium concentrations match concentrations in samples from wells. Two...
Authors
Jeffrey Starn, Amvrossios C. Bagtzoglou, Christopher T. Green
Proper handling of animal tissues from the field to the laboratory supports reliable biomarker endpoints Proper handling of animal tissues from the field to the laboratory supports reliable biomarker endpoints
In the endeavor to assess potential effects to the Gulf of Mexico ecosystem from the Mississippi Canyon 252 incident, referred to as the Deepwater Horizon oil spill, various environmental data have been collected. Whereas initial efforts have included satellite tracking and sediment and water sampling to estimate the geographical scope of oiling, research on biological samples can...
Authors
Heather M. Olivier, Jill A. Jenkins
Simulating water-quality trends in public-supply wells in transient flow systems Simulating water-quality trends in public-supply wells in transient flow systems
Models need not be complex to be useful. An existing groundwater-flow model of Salt Lake Valley, Utah, was adapted for use with convolution-based advective particle tracking to explain broad spatial trends in dissolved solids. This model supports the hypothesis that water produced from wells is increasingly younger with higher proportions of surface sources as pumping changes in the...
Authors
J. Jeffrey Starn, Christopher T. Green, Stephen R. Hinkle, Amvrossios C. Bagtzoglou, Bernard J. Stolp
Accuracy of travel time distribution (TTD) models as affected by TTD complexity, observation errors, and model and tracer selection Accuracy of travel time distribution (TTD) models as affected by TTD complexity, observation errors, and model and tracer selection
Analytical models of the travel time distribution (TTD) from a source area to a sample location are often used to estimate groundwater ages and solute concentration trends. The accuracies of these models are not well known for geologically complex aquifers. In this study, synthetic datasets were used to quantify the accuracy of four analytical TTD models as affected by TTD complexity...
Authors
Christopher T. Green, Yong Zhang, Bryant C. Jurgens, J. Jeffrey Starn, Matthew K. Landon