Fig. 1
a (Top) Time-height plot of MU radar echo power at vertical incidence and high-range resolution from 05:40 to 06:50 LT on 7 June 2015 corresponding to UAV4 and B1. The red (green) line shows the altitude (distance) of UAV4 vs. time. The blue line shows the altitude of B1 vs. time. The label 1 refers to cloud region, 2 to the KH region, and 3 to the stratified region, respectively. These 3 regions are separated by horizontal black lines at 1.80 and 2.15 km, for clarity. See the text for more details. b As in Fig. 1,a but for UAV5 and B2. c (Top) Time-height plot of the vertical velocity measured by MU radar from 05:40 to 06:40 LT on 7 June 2015 during the flight of UAV4. (Center) The corresponding time-height plot of Doppler variance corrected for beam broadening measured at vertical incidence. (Bottom) Aspect ratio defined as the difference (in decibel) between the vertical echo power and the average of the five oblique echo powers. Superimposed are isolines of echo power (Fig. 1a) for PMU = 10 dB showing the edges of the KH braids and the top of the cloudy cells. The horizontal solid lines delineate the KH region (2). The black or red curves show the altitude of UAV4 vs time, as in Fig. 1.a. d As Fig. 1c, but for the radar observations during UAV5