Abstract
A study is presented of the atmospheric aerosol optical thickness (AOT) in the astronomical site of San Pedro Mártir, B. C., Mexico, during the 2000-2008 period. The AOT measurements were made by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrumentation, on board of the NASA Aqua and Terra satellites. Characteristic seasonal values were identified, showing a higher atmospheric transparency in autumn. The best conditions for atmospheric transparency occur in October and November. The annual behavior of MODIS AOT yields average values for SPM during the years 2000-2008 of 0.147±0.103, 0.128±0.090, 0.115±0.081, 0.087±0.066 at 4700, 5500, 6600 and 21300 Å, respectively. We used these mean values to analyze the wavelength dependence and found aerosol scattering slopes α{OIR} ∼ 0.31±0.06, and a relation τ_λ ∼ 0.0061 λ-0.31, for aerosol scattering over the San Pedro Mártir location.
