Global Analysis of Height-Resolved Ice Particle Categories From Spaceborne Lidar

A more accurate representation of ice-phase processes in numerical models necessitates an enhanced understanding of ice-particle microphysics and their respective formation conditions. Prior in situ measurements have noted distinctive ice-particle shape characteristics associated with different cloud systems and geographical locations. The recent advancement in ice-particle backscattering theories enables a more comprehensive exploration of the geographical distribution and seasonal dependence of ice-particle shape categories than ever before. This exploration is being undertaken for the first time using space-borne lidar measurements. Distinct geographical preferences were observed for five different ice-particle categories. Bullets/rosettes were the most common, followed by Voronois, which were especially prevalent in high-level tropical clouds, and 2D columns, which were commonly found in mid- and low-level clouds. Droxtals were primarily observed in high-level subtropical regions. The global distribution of ice-particle types provides valuable insights into the physical processes related to ice cloud particle shape formation, cloud duration, and radiative impacts. An enhanced understanding of ice-particle microphysics associated with different cloud systems and geographical locations is expected to improve the representation of ice clouds in numerical models for better future climate predictions. For such purpose, space-borne lidar observations have been intensively used to characterize the global distribution of cloud phases, as well as ice particle types. Latest theoretical studies have indicated the possibility of further decomposing these ice particle types into more specific ice-particle category information, but had not been applied to actual global observation data. In this work, the geographical distribution of five ice-particle categories was derived based on the theoretical studies using spaceborne lidar data for the first time. It was found that different ice-particle categories had a unique geographical preference for occurrence, along with seasonal and height-dependent characteristics. The global distribution of ice-particle categories obtained in the present study is expected to be useful for understanding the physical processes related to ice-particle shape formation and the ice-particle terminal velocity characteristics relevant to cloud duration. For the first time, spaceborne lidar was used to study meticulously the height-resolved global distribution of five ice-particle categoriesEach cloud-particle type displayed a unique geographical preference for occurrence, along with seasonal and height-dependent characteristicsThe global data on ice-particle types and particle size from radar-lidar synergies promises to be valuable for future cloud modeling studies