Retrieval of nitrogen dioxide stratospheric profiles from ground-based zenith-sky UV-visible observations: validation of the technique through correlative comparisons F. Hendrick1, B. Barret1,*, M. Van Roozendael1, H. Boesch2,**, A. Butz2, M. De Mazière1, F. Goutail3, C. Hermans1, J.-C. Lambert1, K. Pfeilsticker2, and J.-P. Pommereau3 1Institut d’Aéronomie Spatiale de Belgique (IASB-BIRA), Brussels, Belgium 2Institute for Environmental Physics, University of Heidelberg, Germany 3Service d’Aéronomie du CNRS, Verrieres le Buisson, France *now at: Service de Chimie Quantique et Photophysique: atomes, molécules et atmosphères, Université Libre de Bruxelles, Belgium **now at: Jet Propulsion Laboratory, Pasadena, California, USA
Abstract. A retrieval algorithm based on the Optimal Estimation Method (OEM) has been
developed in order to provide vertical distributions of NO2 in the
stratosphere from ground-based (GB) zenith-sky UV-visible observations. It
has been applied to observational data sets from the NDSC (Network for
Detection of Stratospheric Change) stations of Harestua (60° N, 10° E)
and Andøya (69° N, 16° E) in Norway. The information content
and retrieval errors have been analyzed following a formalism used for
characterizing ozone profiles retrieved from solar infrared absorption
spectra. In order to validate the technique, the retrieved NO2 vertical
profiles and columns have been compared to correlative balloon and satellite
observations. Such extensive validation of the profile and column retrievals
was not reported in previously published work on the profiling from GB
UV-visible measurements. A good agreement - generally better than 25% - has been
found with the SAOZ (Système d'Analyse par Observations
Zénithales) and DOAS (Differential Optical Absorption Spectroscopy)
balloons. A similar agreement has been reached with correlative
satellite data from the HALogen Occultation Experiment (HALOE) and Polar Ozone
and Aerosol Measurement (POAM) III instruments above 25km of altitude.
Below 25km, a systematic underestimation - by up to 40% in some cases - of both
HALOE and POAM III profiles by our GB profile retrievals has been observed,
pointing out more likely a limitation of both satellite instruments at these altitudes.
We have concluded that our study strengthens our confidence in the reliability of the
retrieval of vertical distribution information from GB UV-visible observations and
offers new perspectives in the use of GB UV-visible network data for validation purposes.
Citation: Hendrick, F., Barret, B., Van Roozendael, M., Boesch, H., Butz, A., De Mazière, M., Goutail, F., Hermans, C., Lambert, J.-C., Pfeilsticker, K., and Pommereau, J.-P.: Retrieval of nitrogen dioxide stratospheric profiles from ground-based zenith-sky UV-visible observations: validation of the technique through correlative comparisons, Atmos. Chem. Phys., 4, 2091-2106, doi:10.5194/acp-4-2091-2004, 2004.