Multi-scalar analysis of groundwater-surface-atmospheric interactions at the Bonneville Salt Flats, an ephemeral saline pan

Abstract:

The Bonneville Salt Flats is a large, dynamic saline pan in western Utah. Saline pans are unique environments with rapidly fluctuating surface morphologies, water table levels, and fluid compositions. This research uses environmental observations to constrain interactions between hydrology, mineralogy, surface morphology, and the atmosphere on diurnal, seasonal, and annual timescales. This study presents three years of observations of surface and subsurface conditions in a saline pan. Subsurface measurements include water levels, depth transects of temperature and density. Surface measurements include net radiation, temperature, humidity, and pressure, with a three-month period of eddy covariance measurements. The saline pan undergoes distinct stages of flooding (increasing evaporation trend), evaporative concentration (decreasing evaporation trend), and desiccation (minor evaporation). Observations indicate the surface and subsurface of this system are highly coupled. Changes in subsurface temperature and density following some rain events are suggestive of convective flow. Subsurface water levels and densities fluctuate on diurnal timescales with radiative forcing. These observations have implications for mineral growth at the surface and shallow subsurface. Saline pans, furthermore, present unique systems to explore interactions between the hydro-atmos-geosphere.