The reconstruction of a 73-year time series of AOD at 500 nm by using artificial neural networks.
The reconstruction of a 73-year time series of AOD at 500 nm at IZO has been achieved by using artificial neural networks (ANNs) from 1941 to 2001 and AOD measurements directly obtained with a Precision Filter Radiometer (PFR) between 2003 and 2013. The ANN AOD time series has been comprehensively validated against coincident AOD measurements performed with a solar spectrometer Mark-I (1984–2009) and AERONET CIMEL photometers (2004–2009) at IZO, obtaining a rather good agreement on a daily basis (Pearson R=0.97 between AERONET and ANN AOD, and 0.93 between Mark -I and ANN AOD estimates). The ANN method has proved to be a very useful tool for the reconstruction of daily AOD values at 500 nm from meteorological input data, such as the horizontal visibility, fraction of clear sky, and relative humidity, recorded at IZO. This methodology might be extrapolated to other sites, especially those affected by high
dust loads. See García et al. (2016).