On the response of radar-derived properties to hygroscopic flare seeding

Numerical calculations using a cloud model with detailed microphysics are c onducted to investigate the possible effects of hygroscopic flare seeding o n the changes in the spectra of hydrometeors and the resulting radar-derive d properties, such as storm rain mass, rain flux, and rainfall amount. The results indicate that, in continental clouds, seeding can significantly cha nge the distribution functions of the precipitation particles, the radar re flectivity-rainfall (Z-R) relationship, and the radar-derived properties. T herefore, different Z-R relationships derived respectively from unseeded an d seeded clouds should be used to estimate properly the effects of seeding with hygroscopic flares. The results also show that the effects of hygrosco pic seeding on maritime clouds are small and there is little difference in the Z-R relationship and the precipitation properties between the seeded an d the unseeded cases.