Modeling of radiowave scattering in the melting layer of precipitation

In this paper, a new melting layer model called melting layer with spheroidal particles (CFPS in French) is presented. The physical description of the melting layer and the method of scattering calculation used in this model are developed. Two important contributions are the nonmonotonous law for the axial ratio of melting particles and the scattering calculation, which is made by an exact method for a spheroidal particle with any size and any axial ratio. The CFPS model is validated with radar data at 3 and 35 GHz. Results of validation are shown in this paper. Two applications are discussed: the comparison between three other melting layer models (developed by the European Space Agency, Delft University, and Helsinki University) that run faster in time but involve limitations in particle size or particle shape and a radar data inversion process in order to better characterize the melting layer and to retrieve meteorological parameters.

[1]  J. J. Schlesak,et al.  Melting layer attenuation at 28.56 GHz from simultaneous Comstar beacon and 16.5 GHz polarization diversity radar observations , 1981 .

[2]  Wim Klaassen,et al.  Radar Observations and Simulation of the Melting Layer of Precipitation , 1988 .

[3]  Herman Russchenberg,et al.  Backscattering by and propagation through the melting layer of precipitation: a new polarimetric model , 1996, IEEE Trans. Geosci. Remote. Sens..

[4]  H. R. Pruppacher,et al.  A Wind Tunnel and Theoretical Study of the Melting Behavior of Atmospheric Ice Particles. IV: Experiment and Theory for Snow Flakes , 1990 .

[5]  L. P. Ligthart,et al.  A Doppler-polarimetric backscatter model of the melting layer , 1993 .

[6]  Wim Klaassen,et al.  Attenuation and reflection of radio waves by a melting layer of precipitation , 1990 .

[7]  J. Klett,et al.  Microphysics of Clouds and Precipitation , 1978, Nature.

[8]  F. Ulaby,et al.  Dielectric properties of snow in the 3 to 37 GHz range , 1986 .

[9]  G. Olalere Ajayi,et al.  Modeling of a tropical raindrop size distribution for microwave and millimeter wave applications , 1985 .

[10]  Akira Ishimaru,et al.  Wave propagation and scattering in random media , 1997 .

[11]  J. Marshall,et al.  THE DISTRIBUTION OF RAINDROPS WITH SIZE , 1948 .

[12]  R. Gunn,et al.  THE TERMINAL VELOCITY OF FALL FOR WATER DROPLETS IN STAGNANT AIR , 1949 .

[13]  C. Ulbrich.  Natural Variations in the Analytical Form of the Raindrop Size Distribution , 1983 .

[14]  Milton Kerker,et al.  The Scattering of Light and Other Electromagnetic Radiation ~Academic , 1969 .

[15]  V. G. Farafonov,et al.  Optical properties of spheroidal particles , 1993 .

[16]  Jouni Tervonen,et al.  Backward and forward scattering by the melting layer composed of spheroidal hydrometeors at 5-100 GHz , 1996 .

[17]  Henri Sauvageot.  Polarimetric Radar at Attenuated Wavelength as a Hydrological Sensor , 1996 .

[18]  Wei Zhang,et al.  Scattering of radiowaves by a melting layer of precipitation in backward and forward directions , 1994 .

[19]  Irene A. Stegun,et al.  Handbook of Mathematical Functions. , 1966 .