Improvements to the accuracy of measurements of NO2 by zenith-sky visible spectrometers II: errors in zero using a more complete chemical model

Roscoe, H., Charlton, A. J. ORCID: https://orcid.org/0000-0001-8179-6220, Fish, D. J. and Hill, J. G. T. (2001) Improvements to the accuracy of measurements of NO2 by zenith-sky visible spectrometers II: errors in zero using a more complete chemical model. Journal Of Quantative Spectroscopy and Radiative Transfer, 68 (3). p. 337. ISSN 0022-4073 doi: 10.1016/S0022-4073(00)00058-3

Abstract/Summary

Using a flexible chemical box model with full heterogeneous chemistry, intercepts of chemically modified Langley plots have been computed for the 5 years of zenith-sky NO2 data from Faraday in Antarctica (65°S). By using these intercepts as the effective amount in the reference spectrum, drifts in zero of total vertical NO2 were much reduced. The error in zero of total NO2 is ±0.03×1015 moleccm−2 from one year to another. This error is small enough to determine trends in midsummer and any variability in denoxification between midwinters. The technique also suggests a more sensitive method for determining N2O5 from zenith-sky NO2 data.