First retrieval of vertical profiles of turbulence characteristics and horizontal wind velocity from solar transmission measurements at 212 and 405 GHz

摘要

We report on the investigation and successful application of vertical profiling of the structure parameter c-m~2 and of the outer scale L_0 of absorption fluctuations and of the horizontal wind velocity (vector) during daytime by the analysis of solar transmission measurements. The method is relatively simple and straightforward so that the presented (or a similar) technique could be used in the routine remote sensing of daytime c-m~2, L_0, and wind profiles. It requires multiple beams pointing in different directions at the Sun. The retrieved profiles are consistent with the current knowledge of atmospheric physics. Simultaneous in situ wind velocity measurements agree with the retrieved wind velocity in the lowest 100 m above ground within the measurement uncertainties of less than +-2 m/s. The derived values of c-m~2, at 200 m above ground are in good agreement (within a factor of 1.5) with the findings of an earlier investigation at the same test site. Finally, it is shown that irradiance fluctuations of millimeter and submillimeter waves are dominantly affected by humidity fluctuations, even at a dry and elevated site.