Deriving brown carbon from multiwavelength absorption measurements: method and application to AERONET and Aethalometer observations. - Xuan Wang; Heald, Colette L.; Sedlacek, Arthur J.; de Sá, Suzane S.; Martin, Scot T.; Alexander, M. Lizabeth; Watson, Thomas B.; Aiken, Allison C.; Springston, Stephen R.; Artaxo, Paulo (Atmospheric Chemistry & Physics, 2016)