Raman lidar measurements of aerosol extinction and backscattering 2. Derivation of aerosol real refractive index, single-scattering albedo, and humidification factor using Raman lidar

Aerosol 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 {ital n}, and estimate the effective single-scattering albedo {omega}{sub 0}. Values of {ital n} ranged between 1.4{endash}1.5 (dry) and 1.37{endash}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 themore » PCASP can be represented in the form discussed by {ital Hanel} [1976] with the exponent {gamma}=0.3{plus_minus}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. {copyright} 1998 American Geophysical Union« less

[1]  C. Junge,et al.  Air chemistry and radioactivity , 1963 .

[2]  I. Tang,et al.  Phase transformation and growth of aerosol particles composed of mixed salts , 1976 .

[3]  S. Twomey.  The Influence of Pollution on the Shortwave Albedo of Clouds , 1977 .

[4]  I. Tang,et al.  Aerosol growth studies — IV. Phase transformation of mixed salt aerosols in a moist atmosphere , 1978 .

[5]  Michael D. King,et al.  Aerosol size distributions obtained by inversion of spectral optical depth measurements , 1978 .

[6]  B Nilsson,et al.  Meteorological influence on aerosol extinction in the 0.2-40-microm wavelength range. , 1979, Applied optics.

[7]  E. Shettle,et al.  Models for the aerosols of the lower atmosphere and the effects of humidity variations on their optical properties , 1979 .

[8]  Michael D. King,et al.  Determination of the complex refractive index and size distribution of atmospheric particulates from bistatic‐monostatic lidar and solar radiometer measurements , 1980 .

[9]  T. Ackerman,et al.  Absorption of visible radiation in atmosphere containing mixtures of absorbing and nonabsorbing particles. , 1981, Applied optics.

[10]  Gottfried Hänel,et al.  An attempt to interpret the humidity dependencies of the aerosol extinction and scattering coefficients , 1981 .

[11]  R. W. Fenn,et al.  Atmospheric optical properties and meteorological conditions , 1981 .

[12]  T. Nakajima,et al.  Retrieval of the optical properties of aerosols from aureole and extinction data. , 1983, Applied optics.

[13]  Yoram J. Kaufman,et al.  Light Extinction by Aerosols during Summer Air Pollution , 1983 .

[14]  Z. Kam,et al.  Absorption and Scattering of Light by Small Particles , 1998 .

[15]  T. Larson,et al.  Measurement of laboratory and ambient aerosols with temperature and humidity controlled nephelometry , 1985 .

[16]  Christine S. Sloane,et al.  Prediction of ambient light scattering using a physical model responsive to relative humidity: Validation with measurements from detroit , 1985 .

[17]  R. Fraser,et al.  The Relative Importance of Aerosol Scattering and Absorption in Remote Sensing , 1985, IEEE Transactions on Geoscience and Remote Sensing.

[18]  C. Sloane.  Effect of composition on aerosol light scattering efficiencies , 1986 .

[19]  G. de Leeuw,et al.  Humidity effects on the backscatter/extinction ratio. , 1986, Applied optics.

[20]  Teruyuki Nakajima,et al.  Consistency of aerosol size distributions inferred from measurements of solar radiation and aerosols , 1986 .

[21]  Yasuhiro Sasano,et al.  Ratio of aerosol backscatter to extinction coefficients as determined from angular scattering measurements for use in atmospheric lidar applications , 1987 .

[22]  P. Koepke,et al.  Scattering functions of tropospheric aerosols: the effects of nonspherical particles. , 1988, Applied optics.

[23]  M. Stolzenburg,et al.  On the sensitivity of particle size to relative humidity for Los Angeles aerosols , 1989 .

[24]  B. Huebert,et al.  Airborne aerosol inlet passing efficiency measurement , 1990 .

[25]  Y. Sasano,et al.  Aerosol Optical Properties Inferred from Simultaneous Lidar, Aerosol-Counter, and Sunphotometer Measurements , 1990 .

[26]  L. Radke,et al.  Sulfur in particles in Arctic hazes derived from airborne in situ and lidar measurements , 1990 .

[27]  S. Twomey,et al.  Aerosols, clouds and radiation , 1991 .

[28]  Teruyuki Nakajima,et al.  Aerosol Monitoring Using a Scanning Spectral Radiometer in Sendai, Japan , 1991 .

[29]  Eric P. Shettle,et al.  Atmospheric Aerosols: Global Climatology and Radiative Characteristics , 1991 .

[30]  H. Hansson,et al.  Hygroscopic growth of aerosol particles in the Po Valley , 1992 .

[31]  J. Coakley,et al.  Climate Forcing by Anthropogenic Aerosols , 1992, Science.

[32]  Optically equivalent refractive index of atmospheric aerosol particles , 1992 .

[33]  J. Deluisi,et al.  Measured and calculated optical property profiles in the mixed layer and free troposphere , 1992 .

[34]  J. Strapp,et al.  Hydrated and Dried Aerosol-Size-Distribution Measurements from the Particle Measuring Systems FSSP-300 Probe and the Deiced PCASP-100X Probe , 1992 .

[35]  Y. Kaufman,et al.  Algorithm for atmospheric corrections of aircraft and satellite imagery , 1992 .

[36]  J. Kiehl,et al.  The Relative Roles of Sulfate Aerosols and Greenhouse Gases in Climate Forcing , 1993, Science.

[37]  The Airborne Aerosol Inlet Workshop: Meeting report , 1993 .

[38]  Yoram J. Kaufman,et al.  Size distribution and scattering phase function of aerosol particles retrieved from sky brightness measurements , 1994 .

[39]  M. Wendisch,et al.  Variability of aerosol optical parameters by advective processes , 1994 .

[40]  Y Sasano,et al.  Tropospheric aerosol optical properties derived from lidar, sun photometer, and optical particle counter measurements. , 1994, Applied optics.

[41]  Barbara E. Carlson,et al.  Nonsphericity of dust‐like tropospheric aerosols: Implications for aerosol remote sensing and climate modeling , 1995 .

[42]  W. Malm,et al.  Examining the relationship among atmospheric aerosols and light scattering and extinction in the Grand Canyon area , 1996 .

[43]  B. Holben,et al.  Urban/industrial aerosol: Ground‐based Sun/sky radiometer and airborne in situ measurements , 1997 .

[44]  M. Wendisch,et al.  Measurements and modelling of aerosol single-scattering albedo : Progress, problems and prospects , 1997 .

[45]  J. Hansen,et al.  Radiative forcing and climate response , 1997 .

[46]  S. H. Melfi,et al.  Raman lidar measurements of aerosol extinction and backscattering. 1. Methods and comparisons , 1998 .