Single-scattering albedo of smoke retrieved from the sky radiance and solar transmittance measured from ground

A method of aerosol single-scattering albedo retrieval from diffuse radiance measured in the solar almucantar and direct solar measurements is proposed. The aerosol scattering optical thickness is derived from the diffuse radiance by applying a radiative transfer model driven by aerosol microstructure parameters and Mie theory. To improve the accuracy of the scattering optical thickness, the inversion results are acceptable only if the radiance is measured across the total almucantar and is accurately fitted by a theoretical model. The aerosol is assumed as an external mixture of purely scattering particles and soot particles, with the soot approximated as a pure absorber. The criterion for the acceptance of fit is determined from the analysis of the effects of random and systematic errors on the single-scattering albedo retrieval. The method was applied to measurements conducted during the Smoke, Clouds, and Radiation - Brazil (SCAR-B) campaign in August and September 1995. Aerosol radiance data were extensively collected by the Aerosol Robotic Network (AERONET) of ground-based Sun/sky radiometers. The analysis focuses on the studies of the time variability of the biomass burning aerosol in the local Cuiaba area, supplemented by measurements collected in Cuiaba in 1993-1994. The results show reasonable ranges of the aerosol single-scattering albedo variability (for example, single-scattering albedo averages 0.87 ±0.08 at 670 nm). The spectral dependence of the single-scattering albedo has both tendencies: decreasing and increasing with wavelength. The potential reasons causing different spectral behavior are analyzed theoretically.

[1]  Michael D. King,et al.  Sensitivity of constrained linear inversions to the selection of the Lagrange multiplier. [for inferring columnar aerosol size distribution from spectral aerosol optical depth measurements] , 1982 .

[2]  H. Gordon,et al.  Retrieval of the columnar aerosol phase function and single-scattering albedo from sky radiance over the ocean: simulations. , 1993, Applied optics.

[3]  N. O'Neill,et al.  Extraction of bimodal aerosol-size distribution radii from spectral and angular slope (Angstrom) coefficients. , 1993, Applied optics.

[4]  J. Dave.  Importance of Higher Order Scattering in a Molecular Atmosphere , 1964 .

[5]  Manfred Wendisch,et al.  Possibility of refractive index determination of atmospheric aerosol particles by ground-based solar extinction and scattering measurements , 1994 .

[6]  Yoram J. Kaufman,et al.  Retrieval of the real part of the refractive index of smoke particles from Sun/sky measurements during SCAR‐B , 1998 .

[7]  P. Pilewskie,et al.  Pinatubo and pre‐Pinatubo optical‐depth spectra: Mauna Loa measurements, comparisons, inferred particle size distributions, radiative effects, and relationship to lidar data , 1993 .

[8]  J. Gazdag,et al.  A modified fourier transform method for multiple scattering calculations in a plane parallel mie atmosphere. , 1970, Applied optics.

[9]  The atmospheric optical depth spectrum determined from CZCS radiance , 1986 .

[10]  Thomas F. Eck,et al.  Measurements of irradiance attenuation and estimation of aerosol single scattering albedo for biomass burning aerosols in Amazonia , 1998 .

[11]  B. Holben,et al.  Use of sky brightness measurements from ground for remote sensing of particulate polydispersions. , 1996, Applied optics.

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

[13]  C. N. Adams.  Solutions of the equations of radiative transfer by an invariant imbedding approach , 1970 .

[14]  O. Dubovik,et al.  Improved technique for data inversion: optical sizing of multicomponent aerosols. , 1995, Applied optics.

[15]  Yoram J. Kaufman,et al.  Biomass burning aerosol size distribution and modeled optical properties , 1998 .

[16]  John R. Miller,et al.  Multialtitude airborne observations of insolation effects of forest fire smoke aerosols at BOREAS: Estimates of aerosol optical parameters , 1997 .

[17]  D. Blake,et al.  Physical, chemical, and optical properties of regional hazes dominated by smoke in Brazil , 1998 .

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

[19]  E. M. Patterson,et al.  Absorption characteristics of forest fire particulate matter , 1984 .

[20]  M. Mishchenko,et al.  Modeling phase functions for dustlike tropospheric aerosols using a shape mixture of randomly oriented polydisperse spheroids , 1997 .

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

[22]  T. Eck,et al.  Effect of dry‐season biomass burning on Amazon basin aerosol concentrations and optical properties, 1992–1994 , 1996 .

[23]  K. S. Shifrin.  Physical optics of ocean water , 1988 .

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

[25]  J. Vanderlei Martins,et al.  Sphericity and morphology of smoke particles from biomass burning in Brazil , 1998 .

[26]  M. Mishchenko,et al.  Light scattering by polydispersions of randomly oriented spheroids with sizes comparable to wavelengths of observation. , 1994, Applied optics.

[27]  Y. Kaufman,et al.  Passive remote sensing of tropospheric aerosol and atmospheric , 1997 .

[28]  Robert A. Kotchenruther,et al.  Direct Radiative Forcing by Smoke from Biomass Burning , 1997, Science.

[29]  A. Smirnov,et al.  AERONET-a federated instrument network and data archive for aerosol Characterization , 1998 .

[30]  H. Horvath.  Atmospheric light absorption : a review , 1993 .

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

[32]  D. A. Colburn,et al.  Smoke optical depths: Magnitude, variability, and wavelength dependence , 1988 .

[33]  T. Nakajima,et al.  Simultaneous determination of complex refractive index and size distribution of airborne and water-suspended particles from light scattering measurements. , 1982 .

[34]  J. M. Livingston,et al.  Aerosol spectral optical depths: Jet fuel and forest fire smokes , 1990 .

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