Open AccessExperimental determination of the phase function and degree of linear polarization of El Chichón and Pinatubo volcanic ashes
Author(s) -
Muñoz O.,
Volten H.,
de Haan J. F.,
Vassen W.,
Hovenier J. W.
Publication year - 2002
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2001jd000983
Subject(s) - volcano , volcanic ash , radiative transfer , vulcanian eruption , scattering , polarization (electrochemistry) , linear polarization , phase function , mineralogy , phase (matter) , materials science , geology , atmospheric sciences , optics , physics , chemistry , geochemistry , laser , quantum mechanics
We present measurements of the phase function and degree of linear polarization for unpolarized incident light as a function of the scattering angle for El Chichón and Pinatubo volcanic ashes at 633 nm. The results are combined and compared with those for Pinatubo at 442 nm and Lokon volcanic ash at 442 and 633 nm [ Volten et al. , 2001]. The three samples of volcanic ashes consist of micron sized, irregularly shaped particles in random orientation. The results are presented in the form of figures and tables for all three samples. Similarities and differences between the results for the three samples are discussed. The measured phase functions and angular distributions of the polarization can be used to evaluate models used to calculate scattering properties of volcanic ash particles, to constrain scattering properties of volcanic ashes used in radiative transfer calculations, and to retrieve characteristics of (clouds of) volcanic ash particles in the atmosphere from remote sensing data.