Affordable Access

deepdyve-link deepdyve-link
Publisher Website

Polarization lidar observations of backscatter phase matrices from oriented ice crystals and rain.

Authors
Type
Published Article
Journal
Optics Express
1094-4087
Publisher
The Optical Society
Publication Date
Volume
22
Issue
14
Pages
16976–16990
Identifiers
DOI: 10.1364/OE.22.016976
PMID: 25090513
Source
Medline
License
Unknown

Abstract

Oriented particles can exhibit different polarization properties than randomly oriented particles. These properties cannot be resolved by conventional polarization lidar systems and are capable of corrupting the interpretation of depolarization ratio measurements. Additionally, the typical characteristics of backscatter phase matrices from atmospheric oriented particles are not well established. The National Center for Atmospheric Research High Spectral Resolution Lidar was outfitted in spring of 2012 to measure the backscatter phase matrix, allowing it to fully characterize the polarization properties of oriented particles. The lidar data analyzed here considers operation at 4°, 22° and 32° off zenith in Boulder, CO, USA (40.0°N,105.2°W). The HSRL has primarily observed oriented ice crystal signatures at lidar tilt angles near 32° off zenith which corresponds to an expected peak in backscatter from horizontally oriented plates. The maximum occurrence frequency of oriented ice crystals is measured at 5 km, where 2% of clouds produced significant oriented ice signatures by exhibiting diattenuation in their scattering matrices. The HSRL also observed oriented particle characteristics of rain at all three tilt angles. Oriented signatures in rain are common at all three tilt angles. As many as 70% of all rain observations made at 22° off zenith exhibited oriented signatures. The oriented rain signatures exhibit significant linear diattenuation and retardance.

Statistics

Seen <100 times