Lewis, Jasper R.Campbell, James R.Lolli, SimoneStewart, Sebastian A.Tan, IvyWelton, Ellsworth J.2020-09-242020-09-242020-08-18Lewis, J. R., Campbell, J. R., Lolli, S., Stewart, S. A., Tan, I., and Welton, E. J.: Determining Cloud Thermodynamic Phase from the Polarized Micro Pulse Lidar, Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-298, in review, 2020.https://doi.org/10.5194/amt-2020-298http://hdl.handle.net/11603/19712A method to distinguish cloud thermodynamic phase from polarized Micro Pulse Lidar (MPL) measurements is described. The method employs a simple enumerative approach to classify cloud layers as either liquid water, ice water, or mixed-phase clouds based on the linear volume depolarization ratio and cloud top temperatures derived from Goddard Earth Observing System, version 5 (GEOS-5) assimilated data. Two years of cloud retrievals from the Micro Pulse Lidar Network (MPLNET) site in Greenbelt, MD are used to evaluate the performance of the algorithm. The fraction of supercooled liquid water in the mixed-phase temperature regime (−37 °C–0 °C) calculated using MPLNET data is compared to similar calculations made using the spaceborne Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument on board the Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite, with reasonable consistency.24 pagesen-USThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.Public Domain Mark 1.0This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.Text