Astrophysics and Space Science

, Volume 198, Issue 2, pp 253–263 | Cite as

Simulation of atmospheric effects on the emergent radiation over a checkerboard type of terrain

  • T. Takashima
  • K. Masuda
Article

Abstract

To evalute the effect of the non-uniform surface on the radiation field, the upwelling radiation at the top of the atmosphere bounded by the checkerboard type of terrain is computed using the modified doubling method. The terrain is composed of the square Lambert surfaces with two different albedoes. The dimension of the each square is assumed to be 0.5–6 km. The radiance of the terrain is discussed with respect to the atmospheric effect. The observational site is located at altitude 30 km. The corresponding projected point on the ground is located at the center of a square. The solar and observational direction is located in the plane parallel to the checkerboard squares. The atmosphere is assumed to be homogeneous, which is composed of aerosol and molecules, where the model aerosol is of the oceanic or the water soluble types.

Numerical simulation exhibits the extraordinary effect near the edge of each squares. The radiance of the terrain depends upon the difference of albedoes and size of squares. It increases with the increase of the dimension of the square. It decreases with the optical thickness. At large optical thickness, the variation of radiation with zenith direction depends upon the aerosol characteristics. It shows little dependence on the solar zenith angle if less than ∼ 20°.

Keywords

Radiation Field Zenith Angle Optical Thickness Solar Zenith Angle Projected Point 

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References

  1. Radiation Commission, IAMAP: 1986,A Preliminary Cloudless Standard Atmosphere for Radiation Computation, WCP-112, WMO/TD No. 24, World Meteorological Organization, Geneva.Google Scholar
  2. Takashima, T. and K. Masuda: 1992a,Astrophys. Space Sci. 197, 257.Google Scholar
  3. Takashima, T. and K. Masuda: 1992b, ‘Atmospheric Effect on the Upwelling Radiation at the Top of the Atmosphere over a Stream’ (to appear).Google Scholar
  4. Takashima, T. and K. Masuda: 1992c, Simulation of ‘Atmospheric Effect on the Emergent Radiation over a Circular Lake’ (to appear).Google Scholar

Copyright information

© Kluwer Academic Publishers 1993

Authors and Affiliations

  • T. Takashima
    • 1
  • K. Masuda
    • 1
  1. 1.Meteorological Research InstituteTsukuba, IbarakiJapan

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