Improvement in Prediction of Optical Turbulence through Observational Constraints

Optical turbulence, defined by fluctuations of the refractive index of air, is most influenced by fluctuations in temperature (T’) and humidity (q’) that are pronounced near the surface and in the entrainment zone at the top of the PBL. Characterization and prediction of optical turbulence, and hence T’ and q’, is of interest for atmospheric propagation of high energy lasers. Specifically, understanding the spatial variability of optical turbulence has been identified as a research priority.

We utilize atmospheric numerical modeling to characterize the three-dimensional variability of the refractive index structure function (Cn2), and examine the role of surface-atmosphere interactions in modulating the spatial variability of Cn2. Numerical model simulations are evaluated using in situ (including sodar, sonic anemometer, scintillometer, ceilometer, balloon, and etc.) and remotely sensed data collected at the Persistent Data Collection Site established in Hazel Green, AL.