Subsurface Evaporation Estimated from Sensible Heat Balance.

Soil water evaporation is a critical component of the soil surface water balance and the soil surface energy balance. The inability of earlier methods to measure in situ soil water evaporation limits our understanding of the dynamic process of soil water evaporation. In this study, we measured soil temperature and thermal properties with heat pulse sensors. Measurements enabled determination of sensible soil heat fluxes and sensible heat storage changes with time and depth. Based on a sensible heat balance, latent heat fluxes with depth were calculated. Daily soil water evaporation estimates agreed well with Bowen ratio measurements. The heat pulse method shows great promise in measuring in situ soil water evaporation.