Solar radiative fluxes for broken cloud fields above reflecting surfaces

Journal Article · Fri May 01 04:00:00 EDT 1992 · Journal of the Atmospheric Sciences; (United States)

DOI:https://doi.org/10.1175/1520-0469(1992)049<0749:SRFFBC>2.0.CO;2· OSTI ID:5648885

Barker, H W; Davies, J A ^[1]

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1. McMaster Univ., Hamilton, Ontario (Canada)

A statistical bidirectional method for including the effects of underlying reflecting surfaces in Monte Carlo simulations of atmospheric photon transport is presented. It is illustrated for the idealized Lambertian surface and a general particulate surface. It is shown that the simple Lambertian surface should be an adequate approximation (to mildly anisotropic surfaces) for calculation of overall fluxes for broken cloud fields. The problem of incorporating multiple internal reflections of solar radiation between cloud and surface is reviewed, and cloud field reflectances to upwelling radiation r[sub k] as a function of the number of internal reflections k are calculated. Unlike plane-parallel and regular arrays of cloud, all r[sub k] are generally not equal for more realistic scaling cloud fields. Strictly speaking, this prohibits use of the familiar geometric sum formulas for flux calculation in a multiple reflecting system. Fortunately, though fortuitously, the geometric sum formulas can be used in such cases if all r[sub k] are assumed to equal approximately the spherical albedo of the cloud field. 32 refs., 12 figs., 3 tabs.

• OSTI ID: 5648885
• Journal Information: Journal of the Atmospheric Sciences; (United States), Journal Name: Journal of the Atmospheric Sciences; (United States) Vol. 49:9; ISSN 0022-4928; ISSN JAHSAK
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
CALCULATION METHODS
CLOUDS
MATHEMATICAL MODELS
METEOROLOGY
MONTE CARLO METHOD
RADIATIONS
SOLAR FLUX
SOLAR RADIATION
STATISTICAL MODELS
STELLAR RADIATION