Utilization of an acoustic tomography array as a large sonic anemometer/thermometer

Abstract

The temperature, wind velocity, and vertical and horizontal kinematic heat fluxes are important characteristics of the atmospheric surface layer. Point measurements of these meteorological parameters are often not representative due to their horizontal variations. For remote sensing of the area-averaged values of these parameters, we suggest using the acoustic tomography array at the Boulder Atmospheric Observatory (BAO). In this approach, the tomography array (with the horizontal size of 80 m by 80 m) is used, in essence, as a large sonic anemometer/thermometer for measurements of the area-averaged, instantaneous values of temperature and wind velocity. The area-averaged horizontal heat flux is then calculated from a time series of the area-averaged temperature and wind velocity. Feasibility of this approach is studied in numerical simulations of the BAO tomography array with the use of LES fields of temperature and wind velocity. The results obtained show that the area-averaged values of temperature, wind velocity, and horizontal heat flux are reliably reconstructed. Numerical analysis of the LES fields indicates that the area-averaged vertical heat flux might be inferred from the horizontal flux. Preliminary experimental results obtained with the BAO acoustic tomography array show that this remote sensing technique is feasible.