Earth’s surface and shallow (<~100m) subsurface, comprising air, water, biota, organic matter, and Earth materials, encompasses the critical zone (CZ), the dynamic interface between atmosphere, biosphere, hydrosphere, and lithosphere. While it’s straightforward to characterize above-ground CZ,
limited direct observations require near-surface geophysics mapping and monitoring of below-ground CZ architecture and processes. To improve our understanding of CZ processes such as infiltration-runoff, water availability, root-soil interactions, carbon storage, nutrients transport, and contaminant degradation, geophysical methods are often employed to offer a versatile range of measurement scales (cm to km). We request abstracts focusing on: 1) geophysical characterization of subsurface CZ and 2) geophysical monitoring of hydrological and biogeochemical processes. Laboratory to field-based studies spanning from single-point to larger-scale measurements (e.g., aerial surveys) with implications for monitoring of CZ processes in the subsurface, are of particular interest. Studies linking scales of measurement and between geophysical and non-geophysical measurements are also encouraged.

• B - Biogeosciences
• H - Hydrology