Validation summary
To improve the product quality, the formaldehyde product has recently been updated to version 2.8.0, taking effect for NRTI products from 2025-11-26 onwards and for OFFL products from 2025-11-22 onwards. Validation of this new processor version is ongoing and will be reported in the Quarterly Validation Report.
The Sentinel-5p TROPOMI L2_HCHO data product (tropospheric HCHO column; De Smedt et al., 2018) is in good overall agreement with correlative ground-based measurements (NDACC FTIR and NDACC MAX-DOAS) and with the OMI QA4ECV HCHO satellite data. The bias estimate is positive over clean areas, and negative over polluted areas, but meets the mission requirement (see Table below). In clean conditions, the dispersion estimate meets the mission requirement.
| Product ID | Stream | Product | Bias | Dispersion | Special features |
| L2_HCHO | NRTI OFFL RPRO |
HCHO, low | +30% | 9 Pmolec/cm2 | Positive bias, low dispersion over clean areas (<2.5 Pmolec/cm2), Negative bias, high dispersion over polluted areas (>8 Pmolec/cm2) |
| HCHO, high | -30% | 24 Pmolec/cm2 |
A detailed description of the method and a comprehensive discussion of validation results can be found in the Quarterly Validation Report #28: April 2018 - August 2025.
| Latest Quarterly Validation Report | Product info | Current Processor Version |
| #28: April 2018 - August 2025 | See sentinel.esa.int |
02.08.00 |
References
De Smedt, I. et al. Algorithm theoretical baseline for formaldehyde retrievals from S5P TROPOMI and from the QA4ECV project Atmos. Meas. Tech., 11, 2395-2426 (2018) doi:10.5194/amt-11-2395-2018