Concepts

Dimensionless number comparing transport timescale to reaction timescale, used to determine whether transport or reaction processes dominate

X-ray Absorption Near Edge Structure spectroscopy fitting method using reference compound spectra to identify chemical species

The transfer of CO2 from water to atmosphere through gas exchange at the air-water interface

Distribution of carbon between different reservoirs including atmosphere, subsurface, and exported dissolved phases during weathering processes

Physical separation method to isolate soil organic matter pools with different physicochemical protection mechanisms

Subsurface conditions where chemical transport is limited to diffusion rather than advection, creating oxygen-depleted anoxic conditions

Changes in rock porosity and permeability due to mineral dissolution and precipitation reactions during weathering

Lateral movement of river channels through erosion and deposition processes over time

The movement of eroded soil and rock particles by water flow

Overland flow that occurs when rainfall intensity exceeds the rate at which water can enter the soil

Unsaturated zone above the water table where pore spaces contain both air and water

The integrated biogeochemical, hydrological, and ecological processes that control water, energy, and nutrient cycling within a watershed