Determination of the Ground Albedo and the Index of Absorption of Atmospheric Particulates by Remote Sensing. Part I : Theory'

A statistical technique is developed for inferring the optimum values of the ground albedo and the effective imaginary term of the complex refractive index of atmospheric particulates. The procedure compares measurements of the ratio of the hemispheric diffuse to directly transmitted solar flux density at the earth’s surface with radiative transfer computations of the same as suggested by Herman el al. (1975). A detailed study is presented which shows the extent to which the ratio of diffuse to direct solar radiation is sensitive to many of the radiative transfer parameters. Results indicate that the optical depth and size distribution of atmospheric aerosol particles are the two parameters which uniquely specify the radiation field to the point where ground albedo and index of absorption can be inferred. Varying the real part of the complex refractive index of atmospheric particulates as well as their vertical distribution is found to have a negligible effect on the diffuse-direct ratio. The statistical procedure utilizes a semi-analytic gradient search method from least-squares theory and includes a detailed error analysis.

[1]  Benjamin M. Herman,et al.  The Effect of Aerosols on the Earth-Atmosphere Albedo , 1975 .

[2]  T. Ackerman,et al.  Shortwave Radiative Effects of Unactivated Aerosol Particles in Clouds. , 1977 .

[3]  R. Eiden.  Determination of the complex index of refraction of spherical aerosol particles. , 1971, Applied optics.

[5]  Benjamin M. Herman,et al.  Determination of the Effective Imaginary Term of the Complex Refractive Index of Atmospheric Dust by Remote Sensing: The Diffuse-Direct Radiation Method , 1975 .

[6]  R. Eiden.  The elliptical polarization of light scattered by a volume of atmospheric air. , 1966, Applied optics.

[7]  J. Dave.  Intensity and polarization of the radiation emerging from a plane-parallel atmosphere containing monodispersed aerosols. , 1970, Applied optics.

[8]  Glenn E. Shaw,et al.  Investigations of Atmospheric Extinction Using Direct Solar Radiation Measurements Made with a Multiple Wavelength Radiometer. , 1973 .

[9]  A. Green,et al.  Diffuse-direct ultraviolet ratios with a compact double monochromator. , 1978, Applied optics.

[10]  Michael D. King,et al.  A Method for Inferring Total Ozone Content from the Spectral Variation of Total Optical Depth Obtained with a Solar Radiometer , 1976 .

[11]  J D Lindberg,et al.  Measurement of the absorption coefficient of atmospheric dust. , 1974, Applied optics.

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

[13]  S. Twomey.  Pollution and the Planetary Albedo , 1974 .

[14]  P Koepke,et al.  Influence of measured reflection properties of vegetated surfaces on atmospheric radiance and its polarization. , 1978, Applied optics.

[15]  Masayuki Tanaka,et al.  Increase of Global Albedo Due to Air Pollution , 1972 .

[16]  A. K. Cline.  Scalar- and planar-valued curve fitting using splines under tension , 1974, Commun. ACM.

[17]  J. Otterman,et al.  Earth-atmosphere system and surface reflectivities in arid regions from Landsat MSS data , 1976 .

[18]  J. Deluisi,et al.  Results of a Comprehensive Atmospheric Aerosol-Radiation Experiment in the Southwestern United States. Part II: Radiation Flux Measurements and Theoretical Interpretation , 1976 .

[19]  Robert J. Charlson,et al.  Absorption coefficient of atmospheric aerosol: a method for measurement. , 1973, Applied optics.

[20]  M. Griggs.  Aircraft Measurements of Albedo and Absorption of Stratus Clouds, and Surface Albedos , 1968 .

[21]  H. V. Hulst.  Light Scattering by Small Particles , 1957 .

[22]  G. Hänel.  The real part of the mean complex refractive index and the mean density of samples of atmospheric aerosol particles , 1968 .

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

[24]  R. Bryson.  “All Other Factors Being Constant…”: A Reconciliation of Several Theories of Climatic Change , 1968 .

[25]  Wei‐Chyung Wang,et al.  The radiative effect of aerosols in the earth's atmosphere , 1974 .

[26]  D. Lenschow,et al.  STUDY OF A CONTINENTAL SURFACE ALBEDO ON THE BASIS OF FLIGHT MEASUREMENTS AND STRUCTURE OF THE EARTH'S SURFACE COVER OVER NORTH AMERICA* , 1964 .

[27]  Benjamin M. Herman,et al.  The effect of atmospheric aerosols on scattered sunlight , 1971 .

[28]  P. Russell,et al.  Complex Index of Refraction of Airborne Soil Particles , 1974 .

[29]  C. Junge,et al.  THE SIZE DISTRIBUTION AND AGING OF NATURAL AEROSOLS AS DETERMINED FROM ELECTRICAL AND OPTICAL DATA ON THE ATMOSPHERE , 1955 .

[30]  S. Schneider,et al.  Atmospheric Carbon Dioxide and Aerosols: Effects of Large Increases on Global Climate , 1971, Science.

[31]  B. Herman.  A NUMERICAL SOLUTION TO THE EQUATION OF RADIATIVE TRANSFER FOR PARTICLES IN THE MIE REGION , 1965 .