How Well We Can Diagnose the Effects of Coupling of the Regional Atmosphere On ET of An Irrigated Surface Under Extreme Advection of Heat.

The role of imported heat and saturation deficit versus available energy on the energy balance of a cotton field is investigated in a semi-arid region under a range of conditions, including extreme horizontal advection of heat. Using eddy covariance measurements of water vapor fluxes, a modified Penman-Monteith Equation expressing a coupling factor will be used to separate the importance of available energy compared to the import of warm dry air from aloft. Eddy covariance data are analyzed to calculate the vertical flux of saturation deficit at various locations. Several cospectral analyses will reveal the sizes of spatial and temporal scales that contribute to the import of saturation deficit. Finally, vertical profiles of temperature and humidity are used as available to document the values of the mixed layer that are being directed towards the surface.