Open AccessA multi‐instrument approach for characterizing the vertical structure of aerosol properties: Case studies in the Pacific Basin troposphere
Author(s) -
Redemann J.,
Turco R. P.,
Pueschel R. F.,
Fenn M. A.,
Browell E. V.,
Grant W. B.
Publication year - 1998
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 - 10.1029/98jd02005
Subject(s) - troposphere , lidar , aerosol , altitude (triangle) , environmental science , remote sensing , atmospheric sciences , spectrometer , pacific basin , atmosphere (unit) , meteorology , geology , optics , physics , oceanography , geometry , mathematics
During February/March 1994, a series of aircraft‐based aerosol measurements were carried out in the Pacific Basin troposphere using a differential absorption lidar system deployed by NASA Langley, and optical spectrometer probes and a wire‐impactor system operated by NASA Ames. A modified Klett inversion algorithm was applied to extract altitude profiles of aerosol backscattering from the IR lidar signal. The algorithm that we have designed for this purpose utilizes the in situ aerosol measurements to normalize the lidar profile at the aircraft altitude and to supply the lidar ratio as a function of height. The lidar‐derived aerosol backscattering coefficients were then compared to the backscattering coefficients calculated from the in situ measurements. During several local aircraft descents, we found good agreement between the remote lidar and in situ results for the absolute value of the aerosol backscattering coefficient and its altitude variation only when we allowed for several layers with different aerosol refractive indices. The agreement validates our lidar calibration method and provides an indication of the variation in aerosol refractive index as a function of altitude. Two of the three case studies performed in this paper reveal layers of anthropogenic aerosols transported long distances into the Pacific Basin troposphere. A third case implies the existence of a layer of dustlike aerosol particles in the lower troposphere, most likely of Asian origin.