Microphysical Characteristics of Ice Hydrometeors in Hurricanes Harvey and Irma (2017).

Numerical predictions of tropical cyclone intensity and rainfall are sensitive to the microphysical parameterizations. A better understanding the characteristics of hydrometeor and microphysical processes in tropical cyclones is thus important to improve forecasts. However, the observation data for studying microphysics, especially above the freezing level, are limited. One promising approach to this problem is dual-polarization radar measurements, which provide insights into the bulk properties of hydrometeors, such as the phase, size, shape and amounts. In this study, we investigate the spatial distribution of ice hydrometeors within the eyewall and rainbands at various intensity stages of Hurricanes Harvey and Irma in the 2017 Atlantic season. By using the WSR-88D dual-polarization measurements, the ice hydrometeors are classified and the quantitative ice water path is estimated. The characteristics of ice hydrometers between the two hurricanes are further compared. These analysis of the ice hydrometeors in hurricanes will help for future model validation and microphysical parameterization improvements.