Distribution of tropospheric NO2 and aerosols with MAX-DOAS measurements in Uccle, Belgium

Dual-scan ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements of tropospheric nitrogen dioxide (NO2) and aerosols were carried out in Uccle (50.8° N, 4.35° E; Brussels region, Belgium) for 2 years from March 2018 to February 2020.
The MAX-DOAS instrument operated in both UV and visible wavelength ranges in a dual-scan configuration consisting of two sub-modes: (1) an elevation scan in a fixed viewing azimuthal direction and (2) an azimuthal scan in a fixed low elevation angle (2°).
By analyzing the O4 and NO2 differential slant column density (dSCD) in six different wavelength intervals along every azimuthal direction and by applying a new optimal-estimation-based inversion approach presented in Dimitropoulou et al. 2022, the horizontal distribution of the NO2 near-surface concentrations and vertical column densities (VCDs) as well as the aerosol near-surface extinction coefficients are retrieved along 10 azimuthal directions.

This dataset represents the differential slant column density data to perform both the normal MAX-DOAS vertical profile retrieval from the elevation scans, as well as the horizontal profile using the azimuthal scans, by applying the method presented.