Meteorologické radary
Polarimetrická měření
Milan Šálek
salek@chmi.cz













Linear depolarization ratio
LDR=10 log(ZVH/ZHH)
nebo

pol1_r_resampled pol2_r_rot_resampled



fig5_color fig5_color
Hailstorm on 05/06/01 at 20:24 UTC. Elevation is 0.5°
LD – “large drops”
LR – light rain
MR – moderate rain
HR – heavy rain
R/H – rain / hail mixture

013002
Freezing rain on 01/30/02, 19:00 UTC, El = 0.5°


020502
Snow on 02/05/02, 19:00 UTC, El =0.5°


Average Z – ZDR dependencies for rain, freezing rain and snow
z_zdr
Combination of polarimetric, surface, and sounding data is necessary







Conventional and polarimetric relations for radar rainfall estimation
Current NEXRAD formula is used for R(Z)
R(KDP,ZDR) relations were obtained from the analysis of the measured DSDs (about 15000) under
assumption of the equilibrium raindrop shape.

rain_ars2
Fields of three-hour rainfall accumulations for the 23 October 1997 rain event within the ARS
micronetwork

050601_rr1