Submitted to: American Meteorological Society of the Conference on Hydrology Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/16/1998
Publication Date: N/A
Technical Abstract: Semi-arid landscapes represent a significant portion of the land area in the United States as well as in other countries throughout the globe. These areas are often characterized by heterogenous soil types, vegetative cover and complex terrain. The heterogeneity of these types of surfaces can have a significant impact on the hydrological balance of these unique land surfaces. Understanding the surface energy partitioning near the surface particularly as affected by different vegetative biomes can provide valuable insight to the local and regional hydrology of semi-arid regions. In this study changes in energy balance at the surface of two distinct plant communities will be compared and evaluated as functions of land cover and surface roughness. This study was conducted over a two year period at the Jornada Experimental Range in the Jornada Basin near Las Cruces, New Mexico. The Jornada Basin lies within the Chihuahuan Desert and is the largest desert in North America. Eddy covariance and Bowen-ratio measurements were conducted over desert grass and mesquite dune surfaces. In addition appropriate ancillary micrometeorological measurements were also made to help evaluate closure of the surface energy balance equation. Cross-calibration results over a desert grass surface from several eddy covariance systems will be shown to assess the level of confidence when comparing and evaluating fluxes over different semi-arid surfaces. Partitioning of the surface energy budget from Black Grama and Mesquite Dune surfaces into latent and sensible heat fluxes will be presented. Differences in the energy partitioning will be evaluated as a function of dry and wet seasons.