Spatial variability of water vapor turbulent transfer within the boundary layer

Although the physics of evaporation within the inner region of the boundary layer is believed to be well understood, observations of mass-energy exchange processes have been hindered by the limitations of point sensors. A combination of point sensors and active remote sensing, namely, water-Raman Lidar measurements, offers new opportunities to study relatively large areas at temporal and spatial scales previously unattainable. Results from experiments over uniform canopies both confirm some traditional theories and challenge some of the underlying assumptions concerning the homogeneity of the surface-atmosphere interface and the use of point sensors to characterize large areas.This work was performed under the auspices of the U.S. Department of Energy. The authors would like to thank F. Archuleta, J. Archuleta, F. Barnes, W. Clements, K. Muller and W. Porch of LANL, R. Whitis of USDA, R. Jackson and P. Pinter of USDA-WCL, and L. Balick of EG&G for their invaluable time and support.