Estimation and inter-comparison of dust aerosols based on MODIS, MISR and AERONET retrievals over Asian desert regions

This study presents detailed analysis of spatiotemporal variations and trend of dust optical properties i.e., Aerosol Optical Depth(AOD) and Angstrom component over Asian desert regions using thirteen years of data(i.e., 2001–2013) retrieved from Aerosol Robotic Network(AERONET), Moderate Resolution Imaging Spectroradiometer(MODIS) and Multi-angle Imaging Spectroradiometer(MISR). These regions include Solar Village, Dunhuang and Dalangzadgad and are considered as origin of desert aerosols in Asia. Mann–Kendall trend test was used to show the trend of AOD. The relationship of AOD with weather parameters and general AOD trend over different wavelengths has also been shown. AOD's trend has been observed significant throughout the year in Solar Village, while in Dunhuang and Dalanzadgad the significant trend has been found only in peak period(March–June).Analysis show high values of AOD and low values of angstrom in Solar Village during peak period. In Chinese desert regions, high values of AOD have been found during peak period and low values in pre-peak period. Significant relationship has been observed between AOD and average temperature in Solar Village and Dalanzadgad whereas rainfall and wind speed showed no significant impact on AOD in all desert regions.

Estimation of aerosol optical depth in relation to meteorological parameters over eastern and western routes of China Pakistan economic corridor

This study finds out seasonal and monthly variations in Aerosol Optical Depth(AOD)over eastern and western routes of China Pakistan Economic Corridor(CPEC)and the relationship between AOD and meteorological parameters(i.e.,temperature,rainfall and wind speed).The Moderate Resolution Imaging Spectroradiometer(MODIS)and Multi-angle Imaging Spectroradiometer(MISR)data was used from the terra satellite for the period of 2000-2016.This study aims to overtake the conventional view of the purpose of using the satellite datasets.This study takes on to the concept that validated satellite data sets rather should be used for the analysis instead of just validation specifically for our study region.Hence,after comparing MODIS AOD with MISR AOD,only MISR AOD dataset is used for further analysis.The results show a decreasing trend of AOD in summer season,a positive relationship between temperature and AOD during winter and spring seasons whereas a positive relationship between wind speed and AOD in winter and spring seasons over eastern and western routes.Periodic analysis of MODIS AOD and MISR AOD depicts May-Aug as the peak period of aerosol concentration over central Pakistan.The inter-annual analysis shows the aerosol trend remained higher during summer season however rainfall shows the washout effect.Eastern route has higher standard deviation and larger values for aerosol prevalence as compared to western route.The trajectory analysis using the HYSPLIT model suggests the bias of air mass trajectory caused deviation in the aerosol trend in the year 2014.