Energy Balance Model for Imagery and Electromagnetic Propagation: Revised

The optical turbulence structure parameter C(2) sub n typically appears in equations used to estimate the effects of temperature and moisture (gradients) on imagery and electromagnetic propagation. Temperature and moisture gradients can be approximated from sensible and latent from sensible and latent heat flux estimates, by the application of basic Obukhov similarity theory parameterizations, and the fluxes can be obtained from radiation/energy balance equations. Numerous energy balance models exist requiring different kinds and numbers of inputs. The semiempirical model developed and presented in this report was constrained to require a minimum number of conventional measurements at a reference level (2 m). There measurements include temperature, pressure, relative humidity, and windspeed. The model also requires a judgment of soil type and moisture (dry, moist, or saturated), cloud characteristics (tenths of cloud cover and density and an estimate of cloud height), day of the year, time of day, and longitude and latitude of the site. Model estimates of net radiation, sensible, ground, and latent heat fluxes are compared with measured values. Comparisons of C(2) sub n estimates computed from measured versus modeled energy fluxes are also made. Optical turbulence, Atmospheric surface layer, Sensible heat flux, Radiation and energy balance, Latent heat flux.