Refractive index of aerosol particles over the Amazon tropical forest during LBA-EUSTACH 1999 - Guyon, Pascal; Boucher, Olivier; Graham, Bim; Beck, Jens; Mayol Bracero, Olga L; Roberts, Gregory C; Maenhaut, Willy; Artaxo Netto, Paulo Eduardo; Andreae, Meinrat O (Journal of Aerosol Science, 2003)