Daily measurements of the solar aureole were made at the Vacuum Newton Telescope (/D=40 cm) at the Teide Observatory (Tenerife) for various airmasses. We use these measurements to understand how the aureole is produced and to extrapolate visible measurements to the infrared range (1.6 /μm). This information will be used to correct sunspot photometric measurements. This programme is included in the second Aerosol Characterization Experiment (ACE-2) held on Tenerife from mid June to July 1997. During this period a large variety of aerosol measurements were made at different altitudes on the island and by aircraft flying over this area of the North Atlantic Ocean. This information will be used to constrain the physical parameters of the aerosols needed for our extrapolation.