117-45 Experimental Evaluation of Heat Pulse Energy Balance Approach for Measuring Transient Evaporation.



Monday, October 17, 2011
Henry Gonzalez Convention Center, Hall C, Street Level

Pukhraj K. Deol, Soil Science, North Carolina State University, Raleigh, NC, Joshua Heitman, Campus Box 7619, North Carolina State University, Raleigh, NC, Aziz Amoozegar, North Carolina State University, Raleigh, NC, Tusheng Ren, No 2 Yuan Ming Yuan Xi Lu, China Agricultural University, Beijing, , CHINA and Robert Horton, Agronomy Department, Ames, IA
Soil-limited evaporation is difficult to measure or estimate. Deeper understanding of soil-limited evaporation requires detailed investigation of the highly dynamic near-surface zone. Recent research suggests the potential for a sensible energy balance approach to estimate latent heat fluxes from evaporation. Multi-needle heat-pulse probes have the capability to continuously measure near-surface temperature and thermal property profiles at the mm scale necessary to determine the sensible energy balance. These detailed fine-scale measurements can be used to continuously monitor magnitude and depth of transient subsurface evaporation. Full realization of this approach, however, requires further testing and evaluation. We are conducting experiments with objectives to (1) evaluate the heat-pulse energy-balance approach for measuring transient evaporation by comparing it with mass balance under controlled laboratory conditions, and (2) to study the effect of boundary layer conditions on depth and magnitude of subsurface soil water evaporation. Experimental data comparing evaporation estimated using heat-pulse energy-balance approach with mass-balance approach under transient evaporation conditions will be presented.
See more from this Division: S01 Soil Physics
See more from this Session: General Soil Physics: II (Includes Graduate Student Competition)