Global simulations of Cn2 using the weather research and forecast model WRF and comparison to experimental results

Abstract

Electro-optical and laser systems are operated world-wide. Their performance in the outside atmosphere is mainly governed by the strength of optical turbulence Cn2 . The predictability of Cn2 using weather-forecast models is investigated by performing simulations with the Weather Research and Forecast Model (WRF). The WRF output data were combined with a micrometeorological parametrization to derive Cn2 . Simulation runs were performed for locations and times included in our worldwide data set of Cn2 obtained in several field trials over land and over the sea. Experimental data of point and integrated path measurements in the surface layer were compared to model calculations of Cn2 . The regions include different climatic conditions from South Africa, the US, as well as Central and Northern Europe. The applicability of WRF to predict Cn2 at the different locations will be discussed. It will be shown that WRF in a 1.1-km resolution is adequate to provide a first estimate of Cn2.