title: Modified angström exponent for the characterization of submicrometer aerosols.
abstract: The classical Angström exponent is an operationally robust optical parameter that contains size information on all optically active aerosols in the field of view of a sunphotometer. Assuming that the optical effects of a typical (radius) size distribution can be approximated by separate submicrometer and supermicrometer components, we show that one can exploit the spectral curvature information in the measured optical depth to permit a direct estimation of a fine-mode (submicrometer) Angström exponent (alpha(f)) as well as the optical fraction of fine-mode particles (eta). Simple expressions that enable the estimation of these parameters are presented and tested by use of simulations and measurements.
authors: N T
authors: NT
authors: O'Neill
authors: O
authors: O
authors: Dubovik
authors: T F
authors: TF
authors: Eck