High Temporal Resolution AOD Prediction Research Is Based On GNSS PWV

Air quality is closely related to our life.In recent years,the problem of atmospheric environmental quality has become increasingly serious,which has an important impact on human life and health.Aerosol pollution is an important source of atmospheric environmental pollution and one of the principal factors affecting atmospheric environmental quality.Among them,aerosol optical depth(AOD)is one of the critical parameters of aerosols,which is of great significance to the study of aerosol pollution.At present,although various commonly used aerosol optical depth acquisition methods have their own advantages,they generally have the defects of a serious lack of data or low temporal and spatial resolution,which brings much inconvenience to the monitoring of aerosol pollution.With the comprehensive development of Global Navigation Satellite System(GNSS),its application space has been greatly expanded,and its application potential has been brought into full play in all aspects.Atmospheric environment quality is related to human life and health.However,atmospheric environmental quality is not only related to pollution sources,but also meteorological conditions have an important impact on the atmospheric environment and human health.As one of the principal forms of air pollution,aerosol pollution will also be affected by meteorological factors.At present,scholars have found that there is a close relationship between aerosol optical depth and meteorological parameters.Therefore,in order to deeply study the impact of aerosol pollution on air quality and improve the integrity of aerosol optical depth data,it is of huge significance.Therefore,this paper explores the application of GNSS water vapor products in AOD prediction research by combining the advantages of GNSS system,such as high precision,high spatiotemporal resolution,no weather influence and complete data,as well as the characteristics that multi-system GNSS data can improve the effectiveness,stability and accuracy of single system measurement data,and preliminarily explores the feasibility of GNSS water vapor data and AOD in practical application.The main research contents of this paper are as follows:(1)Based on the hourly resolution meteorological data of ERA5 and the hourly resolution zenith total delay(ZTD)data of Crustal Movement Observation Network of China(CMONOC),the hourly resolution Precipitable Water Vapor(PWV)is calculated.The accuracy of GNSS PWV retrieved in this paper is verified by radio sounding(RS),ERA5 PWV and other data sources.The results show that the actual accuracy of GNSS PWV is 2.25 mm,and through the analysis of its daily variation.It is found that it has a certain response to climate events,which further prove that the GNSS PWV calculated in this paper has high accuracy.(2)The correlation between hourly resolution GNSS PWV,pressure,temperature and AOD is analyzed.It is found that there is a positive correlation between GNSS PWV,temperature and AOD in Beijing Tianjin Hebei region,and the correlation is 0.60 and 0.38 respectively;there is a negative correlation between pressure and AOD,and the correlation is-0.34.The above results shows that there is a correlation between AOD and meteorological factors.Based on this conclusion,an AOD adaptive prediction model based on GNSS PWV and meteorological parameters is proposed.Accuracy of the proposed AOD adaptive prediction model is verified by comparing with the traditional multiple linear regression model and non adaptive prediction model.The results show that the accuracy of the AOD adaptive prediction model proposed in this paper is better than that of multiple regression model and non adaptive prediction model.The external coincidence accuracy RMSE and MAE of AOD adaptive prediction model are 0.17 and 0.14 respectively.(3)Based on novel coronavirus pneumonia events,the changes of GNSS PWV and AOD were analyzed from the weekend effect,different population level city,long time sequence anomaly and spatial anomaly.The results show that GNSS PWV and AOD can reflect the weekend effect and the change trend of cities with different population levels,and are consistent with the actual phenomenon.In addition,the characteristics of long sequence and spatial anomaly of GNSS PWV and AOD are consistent with the time of occurrence of new crown pneumonia.It further proves that the trend of GNSS PWV and AOD is closely related to the intensity of human activities.And the ability of GNSS PWV and AOD to be applied in the background of the novel coronavirus pneumonia.