Observations of tornadoes and other convective phenomena with a mobile, 3-mm wavelength, Doppler radar: the spring 1999 field experiment

摘要

In the spring of 1999 a field experiment was conducted in the Southern Plains of the United States, during which a mobile, millimeter-wavelength pulsed Doppler radar from the University of Massachusetts, Amherst, was used by a stormintercept team from the University of Oklahoma to collect data in tornadoes and developing tornadoes. With a 0.18 deg beam antenna, resolution as high as 5-10 m in the azimuthal direction was attained in a tornado on 3 May. Data collected in three supercell tornadoes are described. Features such as eyes, spiral bands, and multiple vortices/wavelike asymmetries along the edge of the eyewall are discussed. Winds approaching 80 m s~(-1) were resolved without folding using the polarization diversity pulse pair technique. Two tornadoes formed at an inflection point in reflectivity where the hook echo and apparent rear-flank downdraft intersected. Finescale transverse bands of reflectivity were evident in one hook echo. Data in a dust devil are also described. Numerous other datasets collected in mesocyclones are also noted. A plan for future data analysis is suggested and a plan for future experiments and upgrades to the radar are proposed.