Aerosol Load-Cloud Cover Correlation: A Potential Clue for the Investigation of Aerosol Indirect Impact on Climate of Europe and Africa

Abstract

Aerosol optical depth (AOD) is a key parameter in atmospheric pollution and climate processes. In this paper, we compared the aerosol loading (550 nm) from 2000–2001 to 2017–2018 and total cloud cover using seasonal, latitudinal and solar activity cycle data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and determined the spectral optical range from the region of relatively clear air (Europe) to the region of more considerable biomass burning activity (Africa). To remove the large annual cycle influence, the data were deseasonalized, allowing exploration of inter-annual variability. Deseasonalization obtains the time series AOD monthly average anomaly over the years for each grid cell. We employ the solar flux index over the regions by correlating the absolute percentage mean difference of aerosol and cloud interactions and validate the result by modeling aerosol and cloud data from 2020 to 2021 using a neural network. AOD and solar flux for Africa show correlations of − 0.638 for 2000–2001 and − 0.218 for Europe, and at the same time, AOD with cloud cover for Africa shows correlations of − 0.129 and 0.360 for Europe. The analysis confirmed an inverse weak correlation of aerosols with cloud cover. This would help resolve the knowledge gap by demonstrating that aerosol and cloud interactions are not only dependent on region but also more dependent on the solar activity cycle and seasons. We observed dependence by the latitude of the aerosol load and solar flux index.