Total column ozone from ground-based spectral radiometric measurements at the Colombian Andes

Remote sensing techniques for total ozone (O₃) quantification have not been extensively explored in Colombia; most investigations rely on in situ measurements from ground-based networks or satellite observations. In topographically constrained urban areas, complex atmospheric dynamics present considerable challenges to conducting remote sensing measurements from ground-based systems. Nevertheless, in this study, the Dobson methodology was employed to estimate the total column O₃ from ground-based ultraviolet solar spectral radiometric measurements in the urban area of a polluted valley in the Colombian Andes. Two measurement campaigns, undertaken in 2020 and 2022 under slightly different atmospheric conditions, were conducted. The findings indicated that even minor variations in local atmospheric pollution levels, associated with air quality and climatological variability, directly influence total ozone estimation. The results were compared with total column O₃ retrieved from the Ozone Monitoring Instrument (OMI) aboard the Aura satellite of the National Aeronautics and Space Administration (NASA). Under partly clear-sky conditions, approximately 50% ( $r=0.55$ ) of the ozone retrieved from ground-based measurements exhibited a linear relationship with ozone values from OMI. Under partly cloudy-sky and heavily polluted conditions, a lack of correlation was observed.