Dual-Wavelength High-Spectral-Resolution Lidar for Profiling Optical Properties of Aerosol and Cloud

Xue Shen,Sijie Chen,Tianfen Zhong,Yudi Zhou,Yupeng Zhang,Dong Liu,Chong Liu,Da Xiao,Nanchao Wang,Yuhang Rong,D Liu,B Gross,Y Wang,F Moshary,Y Wu

doi:10.1051/epjconf/202023702012

Abstract

A dual-wavelength high-spectral-resolution lidar (HSRL) based on an iodine absorption filter and a field-widened Michelson interferometer (FWMI) has been developed to profile backscatter and extinction coefficients of aerosols and clouds accurately. This instrument was tested and calibrated on multiple observations in Hangzhou and Zhoushan, respectively, from August 2018 to April 2019. This paper discusses the design and the internal calibration method of the lidar system in detail, with several typical cases of observations and the analysis of these data products. The optical properties of urban aerosols in Hangzhou and the evolvement of clouds in Zhoushan are presented, respectively.

Highlights

There is a strong need to make more observations on the vertical distribution and optical properties of aerosols and clouds
Our preliminary study shows that the parameters such as spectral depolarization ratio and color ratio can be obtained by adding a lidar of another wavelength on the basis of a single-wavelength high-spectral-resolution lidar (HSRL), which can reduce the discrimination error of component and intensity of aerosols [4]
This paper introduces the first dual-wavelength HSRL independently developed by Zhejiang University

Summary

INTRODUCTION

There is a strong need to make more observations on the vertical distribution and optical properties of aerosols and clouds. Both aerosols and clouds play significant roles in influencing the Earth’s climate, but our limited understanding of them leads to very large uncertainties in our ability to estimate the climate changes. The vertical distribution of the aerosols can induce aerosol-cloud interaction These parameters are difficult to estimate from passive satellite data. Our preliminary study shows that the parameters such as spectral depolarization ratio and color ratio can be obtained by adding a lidar of another wavelength on the basis of a single-wavelength HSRL, which can reduce the discrimination error of component and intensity of aerosols [4]. Some typical results of the initial observation are subsequently presented and analyzed, which demonstrate the system’s performance

The lidar system

Aerosol optical properties

Cloud optical properties