Statistics of depolarization ratio from an airborne backscatter lidar

An important cloud optical property derived from elastic backscatter lidars is depolarization ratio because it is used to determine cloud phase. Statistics and trends of volume depolarization ratio were analyzed for four years, 2003–2007, of Cloud Physics Lidar data during five projects of varying geographic locations and meteorological seasons. The volume depolarization ratio was computed using the parallel and perpendicular polarized 1064 nm channels. The majority of the cloud layers yielded a volume depolarization ratio between 0.3 and 0.6 with the volume depolarization ratio frequency distribution centered at 0.45 for ice clouds and 0.05 for water clouds. On average for ice clouds, volume depolarization ratio increased significantly as temperatures decreased. No trend for water clouds was observed, since all water particles are in theory spherical.

[1]  Leopoldo Stefanutti,et al.  One year of cloud lidar data from Dumont d'Urville (Antarctica): 1. General overview of geometrical and optical properties , 1993 .

[2]  Stuart A. Young,et al.  LIRAD Observations of Tropical Cirrus Clouds in MCTEX. Part I: Optical Properties and Detection of Small Particles in Cold Cirrus* , 2002 .

[3]  Raymond M. Measures,et al.  Laser remote sensing : fundamentals and applications , 1983 .

[4]  J. Reichardt,et al.  Correlations among the optical properties of cirrus‐cloud particles: Implications for spaceborne remote sensing , 2002 .

[5]  K. Sassen.  The Polarization Lidar Technique for Cloud Research: A Review and Current Assessment , 1991 .

[6]  Kenneth Sassen,et al.  A Midlatitude Cirrus Cloud Climatology from the Facility for Atmospheric Remote Sensing. Part II: Microphysical Properties Derived from Lidar Depolarization , 2001 .

[7]  Steven Platnick,et al.  Planning, implementation, and first results of the Tropical Composition, Cloud and Climate Coupling Experiment (TC4) , 2010 .

[8]  Kenneth Sassen,et al.  Observations by Lidar of Linear Depolarization Ratios for Hydrometeors. , 1971 .

[9]  Corinne Le Quéré,et al.  Climate Change 2013: The Physical Science Basis , 2013 .

[10]  A. Thorpe,et al.  THORPEX: a global atmospheric research programme for the beginning of the 21st century , 2004 .

[11]  Michael Hess,et al.  Correlations Among the Optical Properties of Cirrus-Cloud Particles: Microphysical Interpretation , 2002 .

[12]  D. Whiteman,et al.  Subtropical cirrus cloud extinction to backscatter ratios measured by Raman Lidar during CAMEX‐3 , 2004 .

[13]  David M. Winker,et al.  Airborne validation of spatial properties measured by the CALIPSO lidar , 2007 .

[14]  Zhaoyan Liu,et al.  Validating lidar depolarization calibration using solar radiation scattered by ice clouds , 2004, IEEE Geoscience and Remote Sensing Letters.

[15]  Zhaoyan Liu,et al.  Simple relation between lidar multiple scattering and depolarization for water clouds. , 2006, Optics letters.

[16]  V. S. Scott,et al.  Cloud physics lidar: instrument description and initial measurement results. , 2013, Applied optics.

[17]  A. Ansmann,et al.  Retrieval of physical particle properties from lidar observations of extinction and backscatter at multiple wavelengths. , 1998, Applied optics.

[18]  Kenneth Sassen,et al.  Cloud Type and Macrophysical Property Retrieval Using Multiple Remote Sensors , 2001 .

[19]  Paul W. Stackhouse,et al.  The Relevance of the Microphysical and Radiative Properties of Cirrus Clouds to Climate and Climatic Feedback , 1990 .

[20]  Bryan A. Baum,et al.  Identification of cloud phase from PICASSO-CENA lidar depolarization: a multiple scattering sensitivity study , 2001 .