MANDOP Analysis over Complex Orography in the Context of the MAP Experiment

Abstract

The present paper deals with the adaptation of the Multiple Analytical Doppler (MANDOP) analysis to Doppler radar observations over complex orography. The objective, in the context of the Mesoscale Alpine Programme (MAP), is to design a reliable and flexible tool able to process any kind of radar data (airborne/ground based) in order to retrieve mesoscale three-dimensional wind fields over complex terrain with a convective-scale resolution. The various effects of the orography on the wind field (slope winds) and on the radar sampling (ground clutter, shadowing effect) are considered and taken into account in each step of the wind synthesis. In addition to these specific aspects, some numerical improvements are presented that make the method quicker and more objective. The method is validated with quasi-real simulated data, and three different boundary conditions are compared (bottom, top, and both). The analysis is eventually applied to real data gathered during IOP2b of the MAP special observing period (SOP) by the C-band Ronsard and Monte Lema Doppler radars, allowing interpretation of the reflectivity and velocity patterns in close correlation with the orography.