Towards a New MAX-DOAS Measurement Site in the Po Valley: Aerosol Optical Depth and NO2 Tropospheric VCDs
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Authors
Castelli, E.
Pettinari, P.
Papandrea, E.
Premuda, M.
Achilli, A.
Richter, A.
Bösch, T.
Hendrick, F.
Fayt, C.
Beirle, S.
Friedrich, M.M.
Van Roozendael, M.
Wagner, T.
Valeri, M.
Discipline
Earth and related Environmental sciences
Subject
MAX-DOAS
earth observation
remote sensing
Po Valley
Audience
Scientific
Date
2025Metadata
Show full item recordDescription
Pollutants information can be retrieved from visible (VIS) and ultraviolet (UV) diffuse solar spectra exploiting Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) instruments. In May 2021, the Italian research institute CNR-ISAC acquired and deployed a MAX-DOAS system SkySpec-2D. It is located in the “Giorgio Fea” observatory in San Pietro Capofiume (SPC), in the middle of the Po Valley, where it has constantly acquired zenith and off-axis diffuse solar spectra since the 1st October 2021. This work presents the retrieved tropospheric NO2 and aerosol extinction profiles (and their columns) derived from the MAX-DOAS measurements using the newly developed DEAP retrieval code. The code has been validated both using synthetic differential Slant Column Densities (dSCDs) from the Fiducial Reference Measurements for Ground-Based DOAS Air-Quality Observations (FRM4DOAS) project and real measured data. For this purpose, DEAP results are compared with the ones obtained with three state-of-the-art retrieval codes. In addition, an inter-comparison with satellite products from Sentinel-5P TROPOMI, for the tropospheric NO2 Vertical Column Densities (VCDs), and MODIS-MAIAC for the tropospheric Aerosol Optical Depth (AOD), is performed. We find a bias of −0.6 × 1015 molec/cm2 with a standard deviation of 1.8 × 1015 molec/cm2 with respect to Sentinel-5P TROPOMI for NO2 tropospheric VCDs and of 0.04 ± 0.08 for AOD with respect to MODIS-MAIAC data. The retrieved data show that the SPC measurement site is representative of the background pollution conditions of the Po Valley. For this reason, it is a good candidate for satellite validation and scientific studies over the Po Valley.
Citation
Castelli, E.; Pettinari, P.; Papandrea, E.; Premuda, M.; Achilli, A.; Richter, A.; Bösch, T.; Hendrick, F.; Fayt, C.; Beirle, S.; Friedrich, M.M.; Van Roozendael, M.; Wagner, T.; Valeri, M. (2025). Towards a New MAX-DOAS Measurement Site in the Po Valley: Aerosol Optical Depth and NO2 Tropospheric VCDs. , Remote Sensing, Vol. 17, Issue 6, A1035, DOI: 10.3390/rs17061035.Identifiers
url:
Type
Article
Peer-Review
Yes
Language
eng