A5042029816- Climate change and permafrost
- Cryospheric studies and observations
- Hydrology and Watershed Management Studies
- Arctic and Antarctic ice dynamics
- Hydrological Forecasting Using AI
- Groundwater flow and contamination studies
- Soil and Water Nutrient Dynamics
- Landslides and related hazards
- Methane Hydrates and Related Phenomena
- Soil and Unsaturated Flow
- Flood Risk Assessment and Management
- Scientific Computing and Data Management
- Fire effects on ecosystems
- Meteorological Phenomena and Simulations
- Hydrology and Sediment Transport Processes
- Geological Studies and Exploration
- Lattice Boltzmann Simulation Studies
- Soil Moisture and Remote Sensing
- Aerosol Filtration and Electrostatic Precipitation
- Peatlands and Wetlands Ecology
- Smart Materials for Construction
- Seismic Imaging and Inversion Techniques
- Air Quality Monitoring and Forecasting
- Climate variability and models
- Geology and Paleoclimatology Research
Oak Ridge National Laboratory
2017-2024
Government of the United States of America
2023
Pacific Northwest National Laboratory
2023
Utah State University
2023
Los Alamos National Laboratory
2012-2019
Los Alamos National Security (United States)
2017
Columbia University
2004-2011
Abstract The need to understand potential climate impacts and feedbacks in Arctic regions has prompted recent interest modeling of permafrost dynamics a warming climate. A new fine‐scale integrated surface/subsurface thermal hydrology capability is described demonstrated proof‐of‐concept simulations. combines surface energy balance model with recently developed three‐dimensional subsurface models for nonisothermal water flows snow distribution the microtopography. Surface are modeled using...
Abstract Emphasizing the physical intricacies of integrated hydrology and feedbacks in simulating connected, variably saturated groundwater‐surface water systems, Integrated Hydrologic Model Intercomparison Project initiated a second phase (IH‐MIP2), increasing complexity benchmarks first phase. The models that took part intercomparison were ATS, Cast3M, CATHY, GEOtop, HydroGeoSphere, MIKE‐SHE, ParFlow. IH‐MIP2 included tilted v‐catchment with 3‐D subsurface; superslab case expanding slab an...
This work focuses on an improved multicomponent interparticle-potential lattice Boltzmann model. The model results in viscosity-independent equilibrium densities and is capable of simulating kinematic viscosity ratios greater than 1000. External forces are incorporated into the discrete equation, rather through velocity shift as original Shan Chen (hereafter, SC) also requires derivation a momentum conserving effective velocity, which substituted distribution function applies to both single-...
Through taliks—thawed zones extending through the entire permafrost layer—represent a critical type of heterogeneity that affects water redistribution and heat transport, especially in sloping landscapes. The formation taliks as part transition from continuous to discontinuous creates new hydrologic pathways connecting active layer sub-permafrost regions, with significant hydrological biogeochemical consequences. At hilly field sites southern Seward Peninsula, AK, patches deep snow tall...
Abstract Modeling and observation of ground temperature dynamics are the main tools for understanding current permafrost thermal regimes projecting future thaw. Until recently, most studies on have focused vertical heat fluxes. Groundwater can transport in both lateral directions but its influence temperatures at local scales environments is not well understood. In this study we combine field observations from a subarctic fen sporadic zone with numerical simulations coupled water At...
Abstract. Climate change is profoundly transforming the carbon-rich Arctic tundra landscape, potentially moving it from a carbon sink to source by increasing thickness of soil that thaws on seasonal basis. However, modeling capability and precise parameterizations physical characteristics needed estimate projected active layer (ALT) are limited in Earth system models (ESMs). In particular, discrepancies spatial scale between field measurements challenge validation parameterization...
Abstract The presence of permafrost influences the flow paths water through Arctic landscapes and thereby has potential to impact stream discharge thermal regimes. Observations from 11 headwater streams in Alaska showed that July temperatures were higher catchments with more near‐surface permafrost. We apply a fully coupled cryohydrology model investigate if on path depth could cause same pattern groundwater discharging hillslopes streams. simulates surface energy balances, snow, subsurface...
We used a model for permafrost hydrology informed by detailed measurements of soil ice content to better understand the potential risk abrupt thaw triggered melting ground ice, key open question associated with response warming Arctic. Our spatially resolved simulations well-characterized site in polygonal tundra near Utqiaġvik, Alaska, agree well multiple types observations current climate. Projections indicate 63 cm bulk subsidence from 2006 2100 strong-warming Representative Concentration...
Abstract Active layer thickness (ALT), the uppermost of soil that thaws on an annual basis, is a direct control amount organic carbon potentially available for decomposition and release to atmosphere as carbon‐rich Arctic permafrost soils thaw in warming climate. We investigate how key site characteristics affect ALT using integrated surface/subsurface thermal hydrology model. most sensitive followed by snow depth but relatively insensitive water landscape with other conditions held fixed....
Abstract. Meteorological forcing plays a critical role in accurately simulating the watershed hydrological cycle. With advancement of high-performance computing and development integrated models, cycle at high temporal (hourly to daily) spatial resolution (tens meters) has become efficient computationally affordable. These hyperresolution models require meteorological as model input ensure fidelity accuracy simulated responses. In this study, we utilized Advanced Terrestrial Simulator (ATS),...
Abstract Permafrost underlies about one fifth of the global land area and affects ground stability, freshwater runoff, soil chemistry, surface‐atmosphere gas exchange. The depth thawed overlying permafrost (active layer thickness) has broadly increased across Arctic in recent decades, coincident with a period streamflow, especially lowest flows (baseflow). Mechanistic links between active thickness baseflow have recently been explored using linear reservoir theory, but most watersheds behave...
Abstract. The effects of soil property uncertainties on permafrost thaw projections are studied using a three-phase subsurface thermal hydrology model and calibration-constrained uncertainty analysis. null-space Monte Carlo method is used to identify hydrothermal parameter combinations that consistent with borehole temperature measurements at the study site, Barrow Environmental Observatory. Each combination then in forward projection conditions for 21st century (from calendar year 2006...
Abstract In the past three decades, an abrupt, pan‐Arctic acceleration of ice wedge melting has transformed tundra landscapes, spurring formation hummock‐like features known as high‐centered polygons (HCPs). This rapid geomorphic transition profoundly alters regional hydrology and influences surface emissions CO 2 CH 4 . Arctic Alaska, most recent instances degradation have arrested within 15–20 years inception, stabilizing HCP microtopography. However, feedbacks between ground deformation...
We explore the coupling of surface and subsurface flows on fully unstructured meshes that conform to complex soil structures. To accommodate distorted inevitably result from explicit representation structures, we leverage structure Mimetic Finite Difference (MFD) spatial discretization scheme couple flows. The MFD method achieves second-order accuracy maintains local mass conservation meshes. diffusion wave approximation for Richards equation flow, ensuring continuity both pressure flux...
Abstract. Numerical simulations are essential tools for understanding the complex hydrologic response of Arctic regions to a warming climate. However, strong coupling among thermal and hydrological processes on surface in subsurface significant role that subtle variations topography have regulating flow direction storage lead uncertainties. Careful model evaluation against field observations is thus important build confidence. We evaluate integrated surface/subsurface permafrost hydrology...
Abstract Despite the widespread use of integrated hydrology models in a variety applications, consideration multicomponent reactive transport is still not common. The implementation these processes requires coupling at surface‐subsurface interface and efficient solution non‐linear geochemical model that consistent with solution. Advanced Terrestrial Simulator provides flexible multiphysics framework facilitated this process. In work, process kernel (PK) was weakly coupled to PK. turn,...
Fully distributed, integrated surface–subsurface hydrological models (ISSHMs) have seen renewed interest due to availability of better software, high performance computing facilities, and high-resolution, spatially extensive data products. ISSHMs are valuable as tools for advancing system understanding they can resolve multiple processes defined on the plot scale including three-dimensional interaction surface water groundwater. Here, we evaluated an ISSHM, Advanced Terrestrial Simulator...
Abstract. The Energy Exascale Earth System Model (E3SM) Land (ELM) is a state-of-the-art land surface model that simulates the intricate interactions between terrestrial and other components of system. Originating from Community (CLM) version 4.5, ELM has been under active development, with added new features functionality, including plant hydraulics, radiation–topography interaction, subsurface multiphase flow, more explicit use management practices. This study integrates v2.1 Weather...
Integrated, distributed hydrologic models leverage advances in computational power and data accessibility to improve predictive understanding of the water cycle. While impressive this area environmental modeling have been accomplished, such are still rarely used, partially because difficulty integrating model data. This research describes release Watershed Workflow version 1.2, a new library aiming automate enable complex workflows defining inputs high resolution, integrated, models....
Abstract Microtopography, or heterogeneities in the elevation across scales much smaller than domain of interest, plays a critical role surface water retention, surface/subsurface interactions, and runoff. Resolving microtopographic influences on flow requires high‐resolution simulations that are computationally demanding even when considering system isolation more so is one component integrated couple with unsaturated subsurface flow. There thus significant motivation for models allow...