Multi-season Characteristics Of Air Pollutants Detected From Ground-based,satellite And Model-simulated Data Over Lanzhou City

The last twenty years in China are characterized by rapid economic growth and urbanization.Concentration and intensification of human activities are so significant that the natural environment had ceased to conform to normal conditions of human life.Modern cities in China are powerful systems and each one changes within its territory and far beyond.At the same time,the atmosphere,the most mobile and sensitive to contamination of the geographical environment of the Earth,is subjected to significant human impact.High concentration of pollutants in the atmosphere of cities and industrial centers causes great harm to public health and a lot of damage to agriculture,industry,residential buildings,technical facilities,and historical monuments.It is no coincidence that in recent years regional environmental problems have become particularly acute in China.Lanzhou has been currently facing a serious air quality problem,i.e.particulate matters in the air as the key factor has led to serious and increased urban pollution.Thus,it should be significant to master the pollution level and variation of atmospheric pollutants in city air quality evaluation and to obtain reasonable prediction methods to kept control the air quality of the Lanzhou City.Therefore,the aim of the thesis is to study the role of natural and anthropogenic factors in the formation of air pollution in the main industrial center of the NorthWestern part of China,using the methods of mathematical statistics,the Hybrid Single Particle Lagrangian Integrated Trajectory Model(HYSPLIT),the Cloud-Aerosol Lidar and the Infrared Pathfinder Satellite Observations(CALIPSO)and the Ozone Monitoring Instrument(OMI),method of predicting aerosol pollution by Navy Aerosol Analysis and Prediction System(NAAPS),using data obtained from ground-based air quality monitoring stations,as well as data from satellites MODIS(Terra)and Landsat-8.This study is based on the data from 1 January,2003 to 31 December,2016 covering different seasons.To achieve this goal,the following problems are investigated:(1)Making analysis of the main concentrations of pollutants(PM2.5,PM10,NO2,SO2,CO,O3)in atmosphere of Lanzhou City by constructing a complete time series data on the basis of long-term data from air quality monitoring stations and the use of mathematical statistics,correlation and hourly dynamics of the main pollutant concentrations to predict long-term dynamics in the main districts of the city and in the whole city.Analysing the level of variability of pollutants in the annual,seasonal,daily and hourly during the performance of the main pollutants.(2)Making analysis of the overall pollution level in the city based on the API(Air Pollution Index)and the AQI(Air Quality Index)determining the air quality.Determining the air quality grade,the long-term and monthly dynamics of the main types of pollutants.(3)Analysing the meteorological conditions of air pollution,to determine the rate of the natural ability of the city atmosphere to self-cleaning.Determining the relationship between the meteorological parameters and air pollution,as well as to make the relationship between climatic factors and air pollutants.(4)Determining the overall environmental situation in the city and in the surrounding territories,on the basis of remote sensing satellites MODIS(Terra)and Landsat-8,performing calculations of atmospheric aerosol Aerosol Optical Depth(AOD),and determining the Urban Heat Island(UHI),the Land Surface Temperature(LST)and Normalized Difference Vegetation Index(NDVI).Received and pre-processed satellite data would provide information not only on the level of atmospheric pollution in the city’s annual,seasonal and monthly progress,but also would assess the thermal structure of Lanzhou City.(5)On the basis of back-trajectory models of Hybrid Single Particle Lagrangian Integrated Trajectory Model(HYSPLIT),Navy Aerosol Analysis and Prediction System(NAAPS)and the Ozone Monitoring Instrument(OMI),identifying the main sources of incoming of air pollutants from the dusty air masses in the city and surrounding areas,with the possibility of predicting aerosol models,and making vertical analysis of the atmosphere during dusty weather using Drugs Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations(CALIPSO).