Horizontal distribution of tropospheric NO 2 and aerosols derived by dual-scan multi-wavelength multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements in Uccle, Belgium

Dual-scan ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements of tropospheric nitrogen dioxide (NO 2 ) 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 submodes: (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 O 4 and NO 2 differential slant column density (dS... Mehr ...