2008 Joint Annual Meeting (5-9 Oct. 2008): Subsurface Evaporation Estimated from Sensible Heat Balance.

663-12 Subsurface Evaporation Estimated from Sensible Heat Balance.



Tuesday, 7 October 2008
George R. Brown Convention Center, Exhibit Hall E
Xinhua Xiao, Agronomy, Iowa State University, Agronomy Building, Room 2593, Iowa State University, Ames, IA 50010, Robert Horton, Iowa State University, 2543 Agronomy Hall, Iowa State University, Ames, IA 50011, Joshua L. Heitman, Soil Science, North Carolina State University, Campus Box 7619, Raleigh, NC 27695 and Thomas Sauer, USDA-ARS, National Soil Tilth Laboratory, 2110 University Boulevard, Ames, IA 50011-3120
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.