Ozone measurements by zenith-sky spectrometers: an evaluation of errors in air-mass factors calculated by radiative transfer models.
Abstract
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 caused by approximations in the calculation (intensity-weight approximation, ignoring the finite field of view of the instrument); by approximation in the scheme of the calculation (single scattering, ignoring refraction); 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 zenith-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% when averaged over the commonly used range of solar zenith angles.
- Publication:
-
Journal of Quantitative Spectroscopy and Radiative Transfer
- Pub Date:
- September 1995
- DOI:
- 10.1016/0022-4073(95)00085-Y
- Bibcode:
- 1995JQSRT..54..471S
- Keywords:
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- Earth Atmosphere: Ozone;
- Earth Atmosphere: Radiative Transfer