Remote sensing of tropospheric clouds with a dual polarizationradar

摘要

Circularly polarized radiation propagating through regions ofntropospheric clouds are depolarized by the constituents of the clouds inntwo ways: through backscattering and propagation effects. Thenpropagation effects are in turn composed of two components: differentialnphase and differential attenuation. Tropospheric clouds can consist ofnwater droplets, ice crystals, and liquid and solid precipitation. Byncoherently correlating the simultaneous signals received in thenright-hand and left-hand polarization channels of a circularnpolarization radar the presence of aligned particles can be detected andnthis can be used distinguish different components of the cloud. Forninstance, vertical alignment of ice crystals in the upper portions ofnthe cloud are indicative of strong electrification. The degree of thenice crystal alignment is related to the strength of the electric field.nStrong alignment of these ice crystals indicates that the storm has thenpotential to produce lightning