Remote Sensing Of Macro-and Micro-physical Properties Of Aerosol And Water Cloud Using Combined Lidar And Radar

Aerosols and clouds are important atmospheric components,and their radiation effects have strong uncertainties in climate change research,which are related to the aerosols and clouds properties.Lidar and millimeter-wave radar have the advantages of continuous observation and high spatiotemporal resolution,which are the effective means for remote sensing of aerosol and cloud properties.Joint observation of com-bined lidar and millimeter-wave radar for aerosol and cloud properties can give full play to their respective advantages that lidar is conducive to aerosol and small ice detection and millimeter-wave radar is conducive to cloud and precipitation detection.On the one hand,joint observation can provide more information for aerosol and cloud properties in inversion process.On the other hand,joint observation can provide an indispensable and effective way for the study of aerosol and cloud interaction.To study aerosol-cloud interactions and their radiation effects,accurate inversions of their macro-and micro-physical properties are important.Macro-physical properties include optical depth,geometric height,etc.The inversion method of macro-physical properties is simple and direct.Micro-physical properties mainly include particle size distribution,single scattering albedo,etc.The inversion method of micro-physical prop-erties is relatively complex and difficult.In this thesis,the inversion of aerosol micro-physical properties was carried out using the experiment data measured by the self-made multi-wavelength Raman lidar in Wenshui,Shanxi Province and two periods were se-lected as cases.The aerosol extinction coefficients at 355 nm,532 nm wavelength and aerosol backscatter coefficients at 355 nm,532 nm,1064 nm wavelength were derived from the selected observation data.Based on Mie theory,the forward model was con-structed and applied to the inversion of aerosol size distribution from actual experiment data,hence,the vertical profiles of aerosol micro-physical properties such as size dis-tribution and single scattering albedo were obtained.Different from the regularization method commonly used,the basic function of aerosol size distribution was constructed using aerosol component models,which considering the influence of relative humidity on.aerosol.Further,comparisons between inversion results from lidar and sampling detection from aircraft at the same time show that the aerosol number concentration,aerosol volume number concentration,aerosol effective radius of lidar inversion and of aircraft sampling detection have a good consistency in the diameter range from 0.1 um to 3 um on August 8,2013.The inversion of macro and micro-physical properties of cloud was carried out through a three-month joint observation experiment in hefei using combined lidar and millimeter-wave radar.This thesis mainly analyzed the ad-vantages and disadvantages of lidar and millimeter-wave radar in cloud macro-physical properties observation.A merging algorithm was employed for the joint obsevation data to obtain the cloud macro-physical properties and characteristics of cloud vertical distribution.Further,simulated inversion of partical size distribution of water cloud,using combined lidar and millimeter-wave radar,were given,which can be applied to the actual measurement to obtain the vertical profiles of the cloud particle number con-centration,cloud effective radius and cloud liquid water content.The results show that inversion from combined lidar and millimeter-wave radar can obtain a better vertical profile of cloud macro-physical properties,and improve the accuracy of water cloud micro-physical properties by reducing the amount of hypothesis.In addition to ground-based remote sensing,this thesis used ten years observation data of spaceborne lidar CALIOP/CALIPSO,millimeter-wave radar CPR/CloudSat and MODIS satellite to study the aerosol and cloud interaction over east Asia,too.The geo-graphical distributions of aerosol and cloud were given.Then,we analysed the relation-ships between aerosol optical depth and water cloud effective radius and the proportion of precipitation cloud in water cloud.The results show that the aerosol optical thickness and effective radius of water cloud have a positive correlation when cloud liquid water path is small,and a negative correlation when cloud liquid water path is large.This may be related to the meteorological conditions and aerosol types,which need a further study.