The Effects of Three-Body Scattering on Differential Reflectivity Signatures

Abstract Effects of three-body scattering on reflectivity signatures at S and C bands can be seen on the back side of large reflectivity storm cores that contain hail. The fingerlike protrusions of elevated reflectivity have been termed flare echoes or “hail spikes.” Three-body scattering occurs when radiation from the radar scattered toward the ground is scattered back to hydrometeors, which then scatter some of the radiation back to the radar. Three-body scatter typically causes differential reflectivity to be very high at high elevations and to be negative at lower elevations at the rear of the storm core. This paper describes a model that can simulate the essential features of the three-body scattering that has been observed in hailstorms. The model also shows that three-body scatter can significantly affect the polarimetric ZDR (differential reflectivity) radar signatures in hailshafts at very low elevation and thus is a possible explanation of the frequently reported negative ZDR signatures in hails...

[1]  R. Rasmussen,et al.  Melting and Shedding of Graupel and Hail. Part III: Investigation of the Role of Shed Drops as Hail Embryos in the 1 August CCOPE Severe Storm , 1987 .

[2]  A. Zahrai,et al.  Implementation of polarimetric capability for the WSR-88D (NEXRAD) radar , 1997, Proceedings of the IEEE 1997 National Aerospace and Electronics Conference. NAECON 1997.

[3]  V. Bringi,et al.  Hail Detection with a Differential Reflectivity Radar , 1984, Science.

[4]  Constantine A. Balanis,et al.  Antenna Theory: Analysis and Design , 1982 .

[5]  W. Peake.  Interaction of electromagnetic waves with some natural surfaces , 1959 .

[6]  V. Chandrasekar,et al.  Polarimetric Measurements in a Severe Hailstorm , 1993 .

[7]  W. Peake,et al.  Theory of radar return from terrain , 1959 .

[8]  F. Ulaby,et al.  Handbook of radar scattering statistics for terrain , 1989 .

[9]  Roy Rasmussen,et al.  Melting and Shedding of Graupel and Hail. Part I: Model Physics , 1987 .

[10]  V. N. Bringi,et al.  Differential radar scattering properties of model hail and mixed-phase hydrometeors , 1984 .

[11]  V. Chandrasekar,et al.  An Examination of Propagation Effects in Rainfall on Radar Measurements at Microwave Frequencies , 1990 .

[12]  Dusan S. Zrnic,et al.  Three-body scattering produces precipitation signature of special diagnostic value , 1987 .

[13]  Craig F. Bohren,et al.  Radar Backscattering of Microwaves by Spongy Ice Spheres. , 1982 .

[14]  Ezekiel Bahar,et al.  A new unified full wave approach to evaluate the scatter cross sections of composite random rough surfaces , 1996, IEEE Trans. Geosci. Remote. Sens..

[15]  Fawwaz T. Ulaby,et al.  Millimeter-wave bistatic scattering from ground and vegetation targets , 1988 .

[16]  Alexander V. Ryzhkov,et al.  Precipitation and Attenuation Measurements at a 10-cm Wavelength , 1995 .

[17]  Lawrence D. Carey,et al.  CSU-CHILL polarimetric radar measurements from a severe hail storm in eastern Colorado , 1998 .

[18]  K. Aydin,et al.  A computational study of polarimetric radar observables in hail , 1990, IEEE Transactions on Geoscience and Remote Sensing.