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Raman Lidar Measurements of Aerosol Extinction and BackscatteringAerosol backscattering and extinction profiles measured by the NASA Goddard Space Flight Center Scanning Raman Lidar (SRL) during the remote cloud sensing (RCS) intensive operations period (IOP) at the Department of Energy Atmospheric Radiation Measurement (ARM) southern Great Plains (SGP) site during two nights in April 1994 are discussed. These profiles are shown to be consistent with the simultaneous aerosol size distribution measurements made by a PCASP (Passive Cavity Aerosol Spectrometer Probe) optical particle counter flown on the University of North Dakota Citation aircraft. We describe a technique which uses both lidar and PCASP measurements to derive the dependence of particle size on relative humidity, the aerosol real refractive index n, and estimate the effective single-scattering albedo Omega(sub 0). Values of n ranged between 1.4-1.5 (dry) and 1.37-1.47 (wet); Omega(sub 0) varied between 0.7 and 1.0. The single-scattering albedo derived from this technique is sensitive to the manner in which absorbing particles are represented in the aerosol mixture; representing the absorbing particles as an internal mixture rather than the external mixture assumed here results in generally higher values of Omega(sub 0). The lidar measurements indicate that the change in particle size with relative humidity as measured by the PCASP can be represented in the form discussed by Hattel with the exponent gamma = 0.3 + or - 0.05. The variations in aerosol optical and physical characteristics captured in the lidar and aircraft size distribution measurements are discussed in the context of the meteorological conditions observed during the experiment.
Document ID
19990032571
Document Type
Reprint (Version printed in journal)
Authors
Ferrare, R. A. (Hughes STX, Inc. Greenbelt, MD United States)
Melfi, S. H. (Maryland Univ. Baltimore County Catonsville, MD United States)
Whiteman, D. N. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Evans, K. D. (Maryland Univ. Baltimore County Catonsville, MD United States)
Poellot, M. (North Dakota Univ. Grand Forks, ND United States)
Kaufman, Y. J. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Date Acquired
August 19, 2013
Publication Date
August 27, 1998
Publication Information
Publication: Journal of Geophysical Research
Volume: 103
Issue: D16
ISSN: 0148-0227
Subject Category
Meteorology and Climatology
Report/Patent Number
Paper-98JD01647
Funding Number(s)
CONTRACT_GRANT: DOE-83221
Distribution Limits
Public
Copyright
Other