Sensitivity analysis of polarimetric variables at a 5-cm wavelength in rain

Sensitivity of 5-cm-wavelength polarimetric radar measurements to raindrop size and distribution is investigated. At this wavelength, resonance occurs for sizes larger than about 5 mm, and therefore several polarimetric varia bles exhibit nonmonotone dependence on the drop diameter The resonance effe ct is examined for temperatures of 0 degrees, 10 degrees, 20 degrees, and 3 0 degrees C. Through use of truncated gamma distributions (parameterized as a function of rain rate from the Maritime Continent Thunderstorm Experimen t), and truncated Marshall-palmer distributions, the influence of the upper tail of the drop size distribution is brought out This poorly documented r egion of sizes can have a significant effect on some polarimetric variables . These simulations are extended further to include estimates of rain rate from the reflectivity factor Z, the specific differential phase K-DP, the c ombined use of K-DP and differential reflectivity Z(DR), and the combined u se of Z and Z(DR).