A New Analysis for the Retrieval of Three-Dimensional Mesoscale Wind Fields from Multiple Doppler Radar

Abstract

The present study is devoted to a new analysis of the Doppler information from multiple Doppler radar scannings aimed at studying the three-dimensional wind field at mesoscale. This analysis referred to as MANDOP (for Multiple ANalytical DOPpler) is mathematically described. An application of the method to simulated and to real data is also presented in the paper, including a comparison with VAD and DVAD analyses and with observations from radiosoundings and sodar. The method consists in expanding the three wind components in terms of orthonormal functions. Physical constraints, such as the boundary condition at ground level and the continuity equation, are included in the analysis as variational constraints in order to improve the vertical component retrieval. Solving the resulting linear system provides the coefficients for the analytical expansion of the wind. Thus, the wind, as well as its derivatives and associated physical parameters (e.g., vorticity, pressure, and temperature perturbations) may be expressed with an analytical form. The data of any number of radars (at least two) may be analyzed simultaneously without reformulating the problem. When only one radar is available, the coefficients retrieved without ambiguity are provided by the method. Application of MANDOP analysis to real data requires that the time-induced advection problem is solved. This aspect is also addressed in the paper. The solution of this problem benefits from the analytical formulation of the wind.