Development of Algorithm for Discriminating Hydrometeor Particle Types With a Synergistic Use of CloudSat and CALIPSO

M. Kikuchi, H. Okamoto, K. Sato, K. Suzuki, G. Cesana, Y. Hagihara, N. Takahashi, T. Hayasaka, R. Oki

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)


We developed a method for classifying hydrometeor particle types, including cloud and precipitation phase and ice crystal habit, by a synergistic use of CloudSat/Cloud Profiling Radar (CPR) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO)/Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP). We investigated how the cloud phase and ice crystal habit characterized by CALIOP globally relate with radar reflectivity and temperature. The global relationship thus identified was employed to develop an algorithm for hydrometeor type classification with CPR alone. The CPR-based type classification was then combined with CALIPSO-based type characterization to give CPR-CALIOP synergy classification. A unique aspect of this algorithm is to exploit and combine the lidar's sensitivity to thin ice clouds and the radar's ability to penetrate light precipitation to offer more complete picture of vertically resolved hydrometeor type classification than has been provided by previous studies. Given the complementary nature of radar and lidar detections of hydrometeors, our algorithm delivers 13 hydrometeor types: warm water, supercooled water, randomly oriented ice crystal (3D-ice), horizontally oriented plate (2D-plate), 3D-ice + 2D-plate, liquid drizzle, mixed-phase drizzle, rain, snow, mixed-phase cloud, water + liquid drizzle, water + rain, and unknown. The global statistics of three-dimensional occurrence frequency of each hydrometeor type revealed that 3D-ice contributes the most to the total cloud occurrence frequency (53.8%), followed by supercooled water (14.3%), 2D-plate (9.2%), rain (5.9%), warm water (5.7%), snow (4.8%), mixed-phase drizzle (2.3%), and the remaining types (4.0%). This hydrometeor type classification provides observation-based insight for climate model diagnostics in representation of cloud phase and their microphysical characteristics.

Original languageEnglish
Pages (from-to)11,022-11,044
JournalJournal of Geophysical Research: Atmospheres
Issue number20
Publication statusPublished - Oct 27 2017

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Space and Planetary Science
  • Earth and Planetary Sciences (miscellaneous)
  • Atmospheric Science


Dive into the research topics of 'Development of Algorithm for Discriminating Hydrometeor Particle Types With a Synergistic Use of CloudSat and CALIPSO'. Together they form a unique fingerprint.

Cite this