Atmospheric Particulate Properties Inferred from Lidar and Solar Radiometer Observations Compared with Simultaneous In Situ Aircraft Measurements: A Case Study

Abstract

Particulate size and height distributions, complex refractive index and mass loading have been measured and inferred from direct aircraft and indirect lidar-solar radiometer observations made during a unique joint experiment conducted the week of 18 November 1974 in Tucson, Ariz. The aircraft and lidar-solar radiometer measurements were first analyzed independently and the results were then intercompared. Vertical profiles of particulate extinction obtained from the lidar (monostatic) and aircraft measurements were found to be in excellent agreement on both a relative and absolute basis. Lidar (bistatic and monostatic) inferences of particulate mass loading agreed favorably with the aircraft mass monitor measurements. The aircraft and lidar (bistatic) size distribution determinations were found to be similar in shape and agreed in absolute value within an order of magnitude. The mean particle refractive index inferred from the lidar (bistatic) measurements (n = 1.40 ? i0.000) agreed with the index of a significant fraction of the particles identified by electron microscope analysis of impactor samples collected with the aircraft.