Research Of Aerosol Retrieval And Basic Chracteristics From Multi-satellite Remote Sensing Datas

With the rapid development of China's economy,industrial production,the automobile exhaust,and the burning of fossil fuels have been thought as major factors for the increasingly severe air pollution experienced in China in recent years.Under global warming conditions,severe haze pollution,extremely cold spell,short-time heavy rainfall,and lightning disasters also occurred frequently.These phenomena have been serious affect people's normal work and life.Aerosols are important parameters for studying climate change and atmospheric pollution,and are the parameters necessary for quantitative remote sensing.The accuracy,physicochemical properties and spatial distribution of its parameters have been the hotspot in the study of air pollution and climate change,and we understand the weakest part.Therefore,the accurate quantitative retrieval of aerosol properties from multi-source satellite data,in combination with the ground-based observation,seems of scientifically significance for the characterizing 3-D distribution of aerosol,assessing the climate and environmental effect of aerosol.Thesis mainly studied the following contents:First of all,using CALIPSO satellite data retrieval of aerosol optical thickness,at the same time,a correction scheme is put forward in order to improve the inversion accuracy,combining with the ground observation data to validate the retrieval,the correction precision,and analyzes the possible error sources.Results show that the filter after the cloud inversion CALIPSO AOD value is generally lower than ground-based observatories AOD value,and after correction CALIPSO AOD value compared with the ground-based observations of AOD value,in addition to the individual station(Long Fengshan),the other leg of the fitting of the slope and the correlation coefficient,the correction effect is better;CALIPSO satellite and ground station position there will be the result of the validation of effects,including type 2 fitting result was better than other types of fitting results;Different relative humidity on the ground,have effects on satellite AOD,overall whether CALIPSO AOD or the correction of CALIPSO AOD(corrected),fitting slope and fitting coefficient decreases with the increase of relative humidity.Secondly,the spatial distribution of AOD in Jiangxi Province was investigated by using the MODIS data of long time series.The vertical probability distribution and MPH(maximum likelihood height)of aerosol,aerosol and cloud were calculated by using CALIPSO / CALIOP VFM data.It was found that the distribution of aerosol optical thickness in Jiangxi Province gradually increased from south to north.Among them,Jiujiang,Nanchang reached the highest level.In the vertical direction,the aerosol accumulates mainly in the range of 1 ~ 3.5km,and the probability of the mixed state of cloud and aerosol is greater than the separation state.In the vertical height of 2 ~ 4km,the probability of polluting dust in spring is the highest,followed by winter,summer and autumn.And smoke aerosol summer probability of the highest,spring,winter quite,followed by autumn.Finally,for the extreme haze events in Beijing,the haze formation process and the aerosol optical properties were analyzed by using the ground and satellite observations and the meteorological conditions,and the possible sources of pollution were discussed.The results show that the high relative humidity,poor diffusion conditions(low wind speed and stable atmosphere)and secondary transformation of aerosols under high emission and aerosol hygroscopic growth are the main causes of this haze event.During the haze,the AOD 500 nm daily average is 1.15 and the daily average of the water vapor(CWV)is 0.42 cm.Angstrom index and fine particle modal are 1.19 and 0.81,respectively,which indicates that the small aerosol particles are more abundant in the atmosphere and become the main contributors to atmospheric extinction during haze.Satellite observations show that there is a clear aerosol layer in the Beijing area where the aerosol layer is concentrated within 2km of the ground during the haze.The aerosol type is mainly composed of mixed aerosols.