RETRIEVAL OF OPTICAL PROPERTIES OF ATMOSPHERIC AEROSOLS FROM MOMENTS OF THE PARTICLE SIZE DISTRIBUTION

Abstract A technique is described for efficient retrieval of families of smooth model distributions, such as lognormals or modified gammas, from the lower moments of the particle size distribution from which aerosol optical properties can be accurately computed. The Multiple Isomomental Distribution Aerosol Surrogate (MIDAS) technique, along with the quadrature technique of McGraw et al. (1995 Geophys. Res. Lett. 22 , 2929–2932), is evaluated by computing the extinction efficiency, asymmetry parameter, backscatter fraction, 180° backscattering cross section, upscatter fraction, mass scattering efficiency, and a direct shortwave forcing at 8 wavelengths for 28 test distributions derived from field observations of marine, continental, urban and stratospheric aerosols. For the 224 single wavelength evaluations with retrieved modified gammas the average magnitude of error for each of the computed optical properties was 2% or less, with the exception of the 180° backscattering cross section (4%), establishing the accuracy of the technique. It is concluded that this approach is useful for obtaining aerosol optical properties from the first 6 moments of the size distribution, permitting confident determination of these properties from models in which aerosol evolution is represented by evolution of the lower-order moments.

[1]  K. T. Whitby.  THE PHYSICAL CHARACTERISTICS OF SULFUR AEROSOLS , 1978 .

[2]  H Quenzel,et al.  Information content of optical data with respect to aerosol properties: numerical studies with a randomized minimization-search-technique inversion algorithm. , 1981, Applied optics.

[3]  Z. Li,et al.  Aerosol dynamics in the equatorial Pacific marine boundary layer: Microphysics, diurnal cycles and entrainment , 1996 .

[4]  I. Tang,et al.  Water activities, densities, and refractive indices of aqueous sulfates and sodium nitrate droplets of atmospheric importance , 1994 .

[5]  Stephen E. Schwartz,et al.  Sulfate over the North Atlantic and adjacent continental regions: Evaluation for October and November 1986 using a three-dimensonal model driven by observation-derived meteorology , 1994 .

[6]  Stephen E. Schwartz,et al.  Direct shortwave forcing of climate by the anthropogenic sulfate aerosol: Sensitivity to particle size, composition, and relative humidity , 1995 .

[7]  J. W. Fitzgerald,et al.  Aerosol size distributions and optical properties found in the marine boundary layer over the Atlantic Ocean , 1990 .

[8]  K. Snetsinger,et al.  Effect of the eruption of El Chichon on stratospheric aerosol size and composition , 1983 .

[9]  Warren H. White,et al.  Particle size distributions that cannot be distinguished by their integral moments , 1990 .

[10]  P. Mcmurry,et al.  Fine particle size distributions at the Mauna Loa Observatory, Hawaii , 1996 .

[11]  P. Hobbs,et al.  Aerosol size distributions in the cloudy atmospheric boundary layer of the North Atlantic Ocean , 1993 .

[12]  Peter H. McMurry,et al.  Modal Aerosol Dynamics Modeling , 1997 .

[13]  Sonia M. Kreidenweis,et al.  A study of new particle formation and growth involving biogenic and trace gas species measured during ACE 1 , 1998 .

[14]  J. Seinfeld,et al.  Characterization of submicron aerosol size distributions from time‐resolved measurements in the Atlantic Stratocumulus Transition Experiment/Marine Aerosol and Gas Exchange , 1996 .

[15]  P. Russell,et al.  Retrieval of aerosol size distribution moments from multiwavelength particulate extinction measurements , 1989 .

[16]  Robert D. Cess,et al.  The Effect of Tropospheric Aerosols on the Earth's Radiation Budget: A Parameterization for Climate Models , 1983 .

[17]  S. Pratsinis.  Simultaneous nucleation, condensation, and coagulation in aerosol reactors , 1988 .

[18]  Bryan J. Johnson,et al.  Balloonborne measurements of Pinatubo aerosol during 1991 and 1992 at 41°N: Vertical profiles, size distribution, and volatility , 1993 .

[19]  W. White,et al.  On the relationship of aerosol optics to moments of particle size distribution , 1998 .

[20]  P. Quinn,et al.  Processes controlling the distribution of aerosol particles in the lower marine boundary layer during the First Aerosol Characterization Experiment (ACE 1) , 1998 .

[21]  Didier Tanré,et al.  Validation of the first algorithm applied for deriving the aerosol properties over the ocean using the POLDER/ADEOS measurements , 1999, IEEE Trans. Geosci. Remote. Sens..

[22]  Warren J. Wiscombe,et al.  The backscattered fraction in two-stream approximations. , 1976 .

[23]  P. Haagenson,et al.  A study of marine aerosols over the Pacific Ocean , 1986 .

[24]  William Feller,et al.  An Introduction to Probability Theory and Its Applications , 1951 .

[25]  A. Kirkevåg,et al.  Intercomparison of models representing direct shortwave radiative forcing by sulfate aerosols , 1998 .

[26]  J. C. Barrett,et al.  A comparison of some approximate methods for solving the aerosol general dynamic equation , 1998 .

[27]  J. Penner,et al.  Quantifying and minimizing uncertainty of climate forcing by anthropogenic aerosols , 1994 .

[28]  R. McGraw,et al.  A condensation feedback mechanism for oscillatory nucleation and growth , 1984 .

[29]  D. Covert,et al.  Comparison of directly measured CCN with CCN modeled from the number-size distribution in the marine boundary layer during ACE 1 at Cape Grim, Tasmania , 1998 .

[30]  E. Vermote,et al.  Operational remote sensing of tropospheric aerosol over land from EOS moderate resolution imaging spectroradiometer , 1997 .

[31]  P. Mcmurry,et al.  Measurements of new particle formation and ultrafine particle growth rates at a clean continental site , 1997 .

[32]  John N. Porter,et al.  Aerosol size distribution models based on in situ measurements , 1997 .

[33]  V. Mohnen,et al.  Retrieving aerosol optical properties from moments of the particle size distribution , 1997 .

[34]  Robert McGraw,et al.  Description of Aerosol Dynamics by the Quadrature Method of Moments , 1997 .

[35]  Didier Tanré,et al.  Characterization of aerosols over ocean from POLDER/ADEOS‐1 , 1999 .

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

[37]  J. C. Barrett,et al.  Improving the accuracy of the moments method for solving the aerosol general dynamic equation , 1996 .

[38]  Stephen E. Schwartz,et al.  Optical properties of atmospheric aerosols from moments of the particle size distribution , 1995 .

[39]  P. Quinn,et al.  Chemical and optical properties of marine boundary layer aerosol particles of the mid-Pacific in relation to sources and meteorological transport , 1996 .

[40]  S. Kreidenweis,et al.  Air mass characteristics, aerosol particle number concentrations, and number size distributions at Macquarie Island during the First Aerosol Characterization Experiment (ACE 1) , 1998 .

[41]  S. Schwartz,et al.  Properties and evolution of aerosols with size distributions having identical moments , 1998 .