Date of Award
Master of Science
Independent aerosol backscatter and extinction measurements with the high power-aperture Purple Crow Lidar (42.87deg N, 81.38deg W, 225 m) are obtained for the first time. This is achieved through application of a Raman-Lidar technique for determining the field of view of the rotating liquid mercury mirror, and through development of a novel method for isolating the attenuation behaviour of the low-altitude mechanical signal chopper.
Eleven nights of high-altitude (> 12 km) aerosol observations are pre sented with measurements of the intrinsic extinction-to-backscatter aerosol ratio (Lidar ratio). These include cirrus clouds, smoke near the tropopause from biomass burning during June-July 2002 and stratospheric aerosols from the Kasatochi volcanic eruption of August 2008. Detailed structure in the Lidar ratio, reflecting physical particle properties, is observed - in contrast to the single value often assumed by Rayleigh Lidars.
A coincidental measurement by the space-borne Calipso Lidar is found to have good agreement.
Doucet, Paul J., "FIRST AEROSOL MEASUREMENTS WITH THE PURPLE CROW LIDAR: LOFTED PARTICULATE MATTER STRADDLING THE STRATOSPHERIC BOUNDARY" (2009). Digitized Theses. 4048.