Buoyancy and Pressure Perturbations Derived from Dual-Doppler Radar Observations of the Planetary Boundary Layer: Applications for Matching Models with Observations

Abstract

Abstract The technique developed by Gal-Chen in 1978 is used to derive vertical velocities, buoyancy, and pressure perturbations from dual-Doppler radar observations of the planetary boundary layer (PBL). Several approaches to verification are pursued. They include: (a) scan-to-scan temporal continuity of the derived fields; (b) an objective test to find out how well the derived pressure perturbations balance the dynamical equations; (c) comparison of dual-Doppler derived, horizontally averaged fluxes of heat versus in situ measurements and other data sets; and (d) a noteworthy improvement in the quality of the retrieved pressure when tendencies are included. Previous studies indicate that in order for the method to be viable the radars have to resolve the PBL with at least ten vertical levels. One such event occurred on 27 September 1978 during project PHOENIX, conducted at the Boulder Atmospheric Observatory (BAO) 300 m tower. An inversion above a shallow boundary layer of height around 800 m was eroded...