Non-correlation between atmospheric extinction coefficient and TOMS aerosol index at the Canarian Observatories

Satellite data measuring aerosols over the Canary Islands need to be correctly interpreted in accordance with the spatial resolution and spectroscopic channels used. In situ data are still a necessary reference for calibrating and interpreting the aerosol index provided by different spectrometers onboard satellites. A comparison of both techniques (in situ and remote) is discussed in this paper, showing there is no linear correlation between the aerosol index and the extinction coefficient. Here, we present an interpretation of different situations arising and discuss critically the correct interpretation of the aerosol index and images provided by the TOMS in accordance with the dust presence over the Observatories. The aerosol index measured at sectors centered at both Observatories (Observatorio del Roque de los Muchachos -ORM-, on La Palma and Observatorio del Teide -OT-, on Tenerife) is also compared.