Forecasting optical turbulence strength: effects of macroscale meteorology and aerosols

Although optical turbulence is usually modelled with micrometeorology, it is shown here that this can be done successfully too with macrometeorology using meteorological parameters measured with standard weather stations and predicted in standard weather forecasts. This makes it possible to predict C_n² according to weather forecast. Two experimentally-derived models are developed - one for practical use and the other for scientific understanding. Correlation of prediction with measurement is on the order of 90% of more, over large dynamic ranges of meteorological parameters. One interesting aspect of these measurements is the statistical evidence that scintillations are affected by aerosols, particularly under conditions of high total aerosol cross sectional area. This is attributed primarily to increased refractive index changes encountered by radiation which penetrates through the aerosols.