Abstract

From July 28, 1991 until September 26, 1993 NOAA researchers collected 45 nearly simultaneous, collocated, vertical backscatter profiles with ruby (0.693 μm) and CO₂ (10.591 μm) lidars near Boulder, Colorado. We used a graphical technique (Post, 1996) to retrieve information on the microphysical nature of stratospheric aerosol particles arising from the June 15, 1991, eruption of Mt. Pinatubo in the Philippines (15.14°, 120.35°E). Normally three independent backscatter measurements are needed to recover three model size distribution parameters, such as the three lognormal parameters of number density, median radius, and standard deviation. Instead we constrained our solutions using contemporaneous, in-situ, optical particle counter (OPC)-derived, unimodal, lognormal standard deviations from the University of Wyoming’s balloonborne sounding taken 100 km to the north (Deshler et al., 1993), and then retrieved median radius and number density.

© 1997 Optical Society of America