Optical Air Mass

optical air mass

[′äp·tə·kəl ′er ‚mas]
(geophysics)
A measure of the length of the path through the atmosphere to sea level traversed by light rays from a celestial body, expressed as a multiple of the path length for a light source at the zenith.

Optical Air Mass

 

the ratio between the air mass penetrated by sun rays for a given zenith distance of the sun and the air mass that would be penetrated by the rays if the sun were at the zenith. The air mass is assumed to extend from the upper boundary of the atmosphere to the surface of the earth. The concept of optical air mass is used in meteorology in calculating the attenuation of solar radiation in the atmosphere.

REFERENCE

Kurs meteorologii (Fizika atmosfery). Edited by P. N. Tverskoi. Leningrad, 1951.
References in periodicals archive ?
Young, "Revised optical air mass tables and approximation formula," Applied Optics, vol.
(1999) computed the combination of calibration uncertainties and uncertainty in ozone (due to seasonality and atmospheric dynamics) and Rayleigh optical depth (due to the variability in air pressure), for optical air mass 1, in the manner of Russell et al.