Validation of OMPS Suomi NPP and OMPS NOAA?20 Formaldehyde Total Columns With NDACC FTIR Observations

We validate formaldehyde (HCHO) vertical column densities (VCDs) from Ozone Mapping and Profiler Suite Nadir Mapper (OMPS-NM) instruments onboard the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite for 2012–2020 Oceanic Atmospheric Administration-20 (NOAA-20) 2018–2020, hereafter referred to as OMPS-NPP OMPS-N20, with ground-based Fourier-Transform Infrared (FTIR) observations of Network Detection Composition Change (NDACC). OMPS-NPP/N20 HCHO products reproduce seasonal variability at 24 FTIR sites. Monthly has a very good agreement FTIR, showing correlation coefficients 0.83 0.88, respectively. (N20) biases averaged over all sites are ?0.9 (4) ± 3 (6)%. However, clean (with VCDs < 4.0 × 1015 molecules cm?2), positive 20 (32) 6 (18)% occur (N20). At > cm?2, negative ?15% 4% appear OMPS-NPP, but OMPS-N20 shows smaller bias 0.5% 6% due its ground pixel footprints. Therefore, footprint sizes important in distinguishing small-scale plumes. In addition, we discuss correction provide lower limit monthly uncertainty products. The total is 0.7 (0.8) corresponding relative 32 (30)%. case however, decreases 31 (18)%.