| Aerosol is an important component of the atmosphere,although its proportion in the atmosphere is very small,due to the uncertainty of its radiation effect in climate change and assessment,as well as the impact on the environment and human health,aerosol has been attracted widespread study interest in recent years.The aerosol optical properties are important physical properties of aerosols,which is also the focus of aerosol research.The geographical and climatic environment of coastal areas are complex,and the circulation situation is controlled by large-scale weather systems and local sea-land breeze circulation.The sources of aerosols in coastal areas are inland,ocean,and mixed aerosols,resulting in complex aerosol optics charateristics under different meteorological conditions.Objective and accurate analysis of aerosol optical properties based on the unique environmental characteristics of coastal areas is the foundation for the studies of aerosol climate and environmental effects in coastal areas and the improvement of existing models in coastal areas.The detection and retrieval of aerosol optical properties is an important basis for studying the impact of atmospheric aerosols on environmental pollution,climate change and human health.In the study of aerosol optical properties,the characteristics of the atmospheric boundary layer aerosol structure and the hygroscopic growth characteristics of aerosol particles are important research topics.In this dissertation,the optical properties of aerosol particles in the coastal area of Maoming in the light pollution background have been studied comprehensively.This dissertation uses observational data of aerosol optical properties in Maoming area to analyze in detail the change characteristics of the atmospheric boundary layer structure and the hygroscopic growth characteristics of aerosol particles under different circulation and aerosol sources situations.In the study of the structure of the atmospheric boundary layer,this dissertation analyzes the applicability of the MPL-based inversion method of the atmospheric boundary layer height(BLH)at different circulation conditions.Then,a new inversion method is proposed,by combining the sounding and MPL observations.This method combines MPL threshold-method and gradient-method for BLH identification,constrained by BLH derived with sounde RI-method.This method can effectively improve the accuracy of the BLH recognition under complex multi-layer atmospheric boundary layer conditions.Then,the method was applied to the observation,and the evaluation of the atmospheric boundary layer structure under the influence of different circulation situations during the experiment period was obtained and was analyzed.In the study of the hygroscopic growth characteristics of aerosol particles,this dissertation proposes a new inversion method for the hygroscopic growth factor of aerosol extinction,by combining atmospheric visibility(VIS)relative humidity(RH)and aerosol particle number concentration(PNC).Then,the hygroscopic growth factor of aerosol extinction under pollution conditions in Maoming and Qingdao area was derived based on the new method and the field measurement data.Finally,this dissertation conducts a preliminary study on the optical engineering application of aerosol optical properties.The sky background radiation was simulated by the radiation transmission model MODTRAN5 with the default general atmospheric mode and the custom atmosphere model designed based on the field measurements.Simulation results were compared with observed background noise of the micropulse lidar(MPL).It was found that the simulation with the custom atmosphere model is more consistent with the MPL observations,indicating that the custom atmosphere model can effectively improve the accuracy of the sky background radiation simulation results.Further studies of aerosol scattering property,aerosol size information and cloud optic property retrievals based on this method will be performed in the near future. |
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