Effects of El Niño/La Niña on the climatic values of aerosol optical thickness for the Valdivia city, Chile

The Moderate Resolution Imaging Spectroradiometer (MODIS) (Aqua and Terra satellites) was used to calculate the climatic values of aerosol optical thickness (AOT) with the wavelength of 550nm for the Valdivia city in Chile within the period of 2002-2016 years. The yearly changes trends of the average monthly AOT values for the city area were identified by the statistical analysis. It was obtained that the MODIS satellite data can be used to examine the effect of the volcanic aerosol on a medium-scale regional level. The results also showed that the anthropogenic atmospheric pollution of the Valdivia city can't be determined by the MODIS satellite data of AOT. A detailed analysis of the El Niño and La Niña periods showed the differences between the amount of the aerosols in the atmospheric column for the each period. These differences are directly related to the variability of the atmospheric circulation within El Niño and La Niña periods.