A5074395966- Methane Hydrates and Related Phenomena
- Ionosphere and magnetosphere dynamics
- Geophysics and Gravity Measurements
- Seismic Waves and Analysis
- Hydrology and Watershed Management Studies
- Geology and Paleoclimatology Research
- Groundwater and Isotope Geochemistry
- Groundwater flow and contamination studies
- Soil and Water Nutrient Dynamics
- Soil and Unsaturated Flow
- Soil Carbon and Nitrogen Dynamics
- Hydrocarbon exploration and reservoir analysis
- Peatlands and Wetlands Ecology
- Coastal wetland ecosystem dynamics
- Atmospheric and Environmental Gas Dynamics
- Soil erosion and sediment transport
- Hydrology and Sediment Transport Processes
- Water Quality and Resources Studies
- Plant Water Relations and Carbon Dynamics
- Fish Ecology and Management Studies
- Hydrological Forecasting Using AI
- Soil Geostatistics and Mapping
- Water Quality and Pollution Assessment
- Karst Systems and Hydrogeology
- Climate change and permafrost
Oregon State University
2019-2025
Corvallis Environmental Center
2022
University of Kansas
2014-2019
Kansas State University
2019
Lawrence University
2019
Pennsylvania State University
2013-2018
James Madison University
2016
Florida International University
2010-2013
University of Florida
2002
Abstract Earth System Models (ESMs) are essential tools for understanding and predicting global change, but they cannot explicitly resolve hillslope‐scale terrain structures that fundamentally organize water, energy, biogeochemical stores fluxes at subgrid scales. Here we bring together hydrologists, Critical Zone scientists, ESM developers, to explore how hillslope may modulate grid‐level fluxes. In contrast the one‐dimensional (1‐D), 2‐ 3‐m deep, free‐draining soil hydrology in most land...
Abstract Headwater catchments are the fundamental units that connect land to ocean. Hydrological flow and biogeochemical processes intricately coupled, yet their respective sciences have progressed without much integration. Reaction kinetic theories prescribe rate dependence on environmental variables (e.g., temperature water content) advanced substantially, mostly in well‐mixed reactors, columns, warming experiments considering characteristics of hydrological at catchment scale. These shown...
Volcanic provinces are among the most active but least well understood landscapes on Earth. Here, we show that central Cascade arc, USA, exhibits systematic spatial covariation of topography and hydrology linked to aging volcanic bedrock, suggesting controls landscape evolution. At crest, a locus Quaternary volcanism, water circulates deeply through upper [Formula: see text]1 km crust transitions shallow dominantly horizontal flow as rocks age away from arc front. We argue this pattern...
We report natural remanent magnetization (NRM) directions and geomagnetic paleointensity proxies for part of the Matuyama Chron (0.9–2.2 Ma interval) from two sites located on sediment drifts in Iceland Basin. At Ocean Drilling Program Sites 983 984, mean sedimentation rates late are 15.9 11.5 cm kyr −1 , respectively. For older record (>1.2 Ma), oxygen isotope data too sparse to provide sole basis age model construction. The resemblance volume susceptibility a reference δ 18 O led us...
Abstract. Solute concentrations in stream water vary with discharge patterns that record complex feedbacks between hydrologic and biogeochemical processes. In a comparison of three shale-underlain headwater catchments located Pennsylvania, USA (the forested Shale Hills Critical Zone Observatory), Wales, UK peatland-dominated Upper Hafren forest-dominated Hore the Plynlimon forest), dissimilar concentration–discharge (C–Q) behaviors are best explained by contrasting landscape distributions...
Abstract Why do solute concentrations in streams remain largely constant while discharge varies by orders of magnitude? We used a new hydrological land surface and reactive transport code, RT‐Flux‐PIHM, to understand this long‐standing puzzle. focus on the nonreactive chloride (Cl) magnesium (Mg) Susquehanna Shale Hills Critical Zone Observatory (SSHCZO). Simulation results show that stream comes from runoff (Q s ), soil lateral flow L deeper groundwater G with Q contributing >70%. In...
To better understand flow pathways and patterns in the subsurface, a stable isotope monitoring network was established at Susquehanna‐Shale Hills Critical Zone Observatory (SSHCZO). Soil water samples were collected approximately biweekly using suction‐cup lysimeters installed multiple depths along four different transects catchment. Groundwater stream daily valley automatic samplers, while precipitation automatically on an event basis. The 3+ years (2008–2012) of data showed strong seasonal...
The hydrologic connectivity between hillslopes and streams impacts the geomorphological evolution of catchments. Here, we propose a conceptual model for hydrogeomorphological Susquehanna Shale Hills Critical Zone Observatory (SSHCZO), first-order catchment developed on shale in central Pennsylvania, U.S.A. At SSHCZO, majority available water (the difference incoming meteoric outgoing evapotranspiration) flows laterally to outlet as interflow, while rest is transported by regional groundwater...
Abstract. Carbonate weathering is essential in regulating atmospheric CO2 and carbon cycle at the century timescale. Plant roots accelerate by elevating soil via respiration. It however remains poorly understood how much rooting characteristics (e.g., depth density distribution) modify flow paths weathering. We address this knowledge gap using field data from reactive transport numerical experiments Konza Prairie Biological Station (Konza), Kansas (USA), a site where woody encroachment into...
Abstract Rooting depth is an ecosystem trait that determines the extent of soil development and carbon (C) water cycling. Recent hypotheses propose human‐induced changes to Earth's biogeochemical cycles propagate deeply into subsurface due rooting from agricultural climate‐induced land cover changes. Yet, lack a global‐scale quantification responses human activity limits knowledge hydrosphere‐atmosphere‐lithosphere feedbacks in Anthropocene. Here we use data sets demonstrate root...
Abstract Soil biota generates carbon that exports vertically to the atmosphere (CO 2 ) and transports laterally streams rivers (dissolved organic inorganic carbon, DOC DIC). These processes, together with chemical weathering, vary flow paths across hydrological regimes; yet an integrated understanding of these interactive processes is still lacking. Here we ask: How what extent do subsurface transformation, solute export differ structure regimes? We address this question using a hillslope...
The depth distribution of soil organic carbon (SOC) is governed by the interaction many ecosystem features, including differential C inputs in shallow and deep soils redistribution via water flow through profile. In C-rich Mollisols particular, we need to better understand degree which conversion native prairie cultivated lands changing loss retention. We probed multiple mechanisms driving these processes using two approaches: one leverages a regional-scale dataset derived from Natural...
Roots and associated microbes generate acid-forming CO2 organic acids accelerate mineral weathering deep within Earth’s critical zone (CZ). At the Calhoun CZ Observatory in USA’s Southern Piedmont, we tested hypothesis that deforestation-induced root losses reduce root- microbially-mediated agents well below maximum density (to 5 m), impart land-use legacies even after ~70 y of forest regeneration. In forested plots, declined with depth to 200 cm; cultivated roots approached zero at depths...
Abstract A comprehensive cross‐biome assessment of major nitrogen (N) species that includes dissolved organic N (DON) is central to understanding interactions between inorganic nutrients and matter in running waters. Here, we synthesize stream water chemistry across biomes find the composition pool shifts from highly heterogeneous primarily comprised N, tandem with (DOM) becoming more N‐rich, response nutrient enrichment human disturbances. We identify two critical thresholds total (TDN)...
Abstract Earth's Critical Zone (CZ), the near‐surface layer where rock is weathered and landscapes co‐evolve with life, profoundly influenced by type of underlying bedrock. Previous studies employing CZ framework have focused primarily on dominated silicate rocks. However, carbonate rocks crop out approximately 15% ice‐free continental surface provide important water resources ecosystem services to ∼1.2 billion people. Unlike silicates, minerals weather congruently high solubilities rapid...
Abstract Fluvial silicon (Si) plays a critical role in controlling primary production, water quality, and carbon sequestration through supporting freshwater marine diatom communities. Geological, biogeochemical, hydrological processes, as well climate land use, dictate the amount of Si exported by streams. Understanding regimes—the seasonal patterns concentrations—can help identify processes driving export. We analyzed concentrations from over 200 stream sites across Northern Hemisphere to...