A. Sarkissian et al., OZONE MEASUREMENTS BY ZENITH-SKY SPECTROMETERS - AN EVALUATION OF ERRORS IN AIR-MASS FACTORS CALCULATED BY RADIATIVE-TRANSFER MODELS, Journal of quantitative spectroscopy & radiative transfer, 54(3), 1995, pp. 471-480
Calculations of air-mass factors (AMFs) for ground-based zenith-sky UV
-visible spectrometers are presented and discussed. Causes and size of
errors in AMFs of ozone in the visible are evaluated. Errors can be c
aused by approximations in the calculation (intensity-weight approxima
tion, ignoring the finite field of view of the instrument); by approxi
mation in the scheme of the calculation (single scattering, ignoring r
efraction); or by variable geophysical parameters (vertical profile of
constituents). These relative errors in AMF cause identical relative
errors in vertical columns of ozone deduced from measurements by zenit
h-sky spectrometers. The mean of the relative errors of ozone AMFs due
to using one set of AMFs for all seasons and locations is +/- 2.4% wh
en averaged over the commonly used range of solar zenith angles.