Abstract Number: 74 Working Group: Aerosol Modeling
Abstract This study presents variability of aerosol over south Asia and its impact on solar radiation using CERES-derived and AERONET-measured observations for long period (~17 years from March 2000 to June 2016). Spatial distributions and trends are shown for CERES-derived parameters like as aerosol optical depth at 550 nm (AOD550), cloud optical depth (COD), photosynthetically active radiation (PAR) and shortwave (SW) fluxes over India. The CERES-derived monthly mean AOD550 values range from ~0.1 to 1.5 and AERONET -measured AOD500 are from 0.03 to 1.6 over India. The highest monthly mean AOD500 (~1.6) is also found at New Delhi (ground-measured Microtops) and lowest AOD500 (~0.03) at Nainital (AERONET -measured). However, both CERES-derived and AERONET -measured spectral AODs are also high (~1.0) at Delhi, Kanpur and Gandhi College during post-monsoon months possibly due to fossil fuel and biomass burning. The highest increasing AOD550 trends are found at Gandhi College (~0.1/decade) and at IIT Khargpur (~0.12/decade) in lower IGP region due to anthropogenic activities. Moderate increasing AOD550 trends (about ~0.05 to 0.06 per decade) are found at Delhi, Kanpur and Pune due to industrialization and urbanization. Increasing trend of CERES-derived AOD550 is found about 0.03/decade at Nainital, but ground-measured AOD500 values are showing decrease trend. The spatial trend range for AOD550 is from ~-0.12 (54%) to ~0.12 (47%), for COD from~-1.2 (23%) to ~0.7 (26%), for PAR from~-4 (6.1%) to ~5 (6%) and for SW from ~-7 (6.1%) to ~15 (6.5%), respectively over India. The negative trend shows decreasing in both fluxes PAR and SW radiation when increasing AOD550 trend over IGP of India.