Simple adjoint retrievals of wet-microburst winds and gust-front winds from single-Doppler radar data

The simple adjoint method for retrieving the low-altitude winds from single -Doppler scans is modified and tested for two events: the wet-microburst ev ent and the gust-front event observed simultaneously by two radars during t he Federal Aviation Administration-1990 summer field experiment at Orlando Airport. For the wet microburst, 42 consecutive wind fields are retrieved f rom each radar and the rms errors (measured by the rms difference between t he retrieved and dual-Doppler analyzed winds) range from 1.1 to 4.9 m s(-1) , and the averaged error is 2.4 m s(-1). For the gust front, 22 consecutive wind fields are retrieved from each radar, the rms errors range from 1.2 t o 2.9 m s(-1), and the averaged error is 1.9 m s(-1). The rms error and spa tial correlation between the retrieved and analyzed cross-beam tangential w inds exhibit strong temporal variations for the wet microburst and moderate temporal variations for the gust front. The rms error is found to be tempo rally correlated to the rms amplitude of the retrieved radial-momentum forc ing for the wet microburst.