The OMPS-N20 L2 NM Formaldehyde (HCHO) Total Column swath orbital product provides formaldehyde measurements from the Ozone Mapping and Profiling Suite (OMPS) Nadir-Mapper (NM) instrument on the NOAA-20 (JPSS-1) satellite. The total column HCHO amount is derived from radiances at wavelengths between 328.5 and 356.5 nm. Each granule contains data from the daylight portion of each orbit measured for a full day. Spatial coverage is global (-90 to 90 degrees latitude), and there are about 14.5 orbits per day. Each has typically 1201 swaths. The swath width of the NM is about 2800 km. Prior to orbit 6419 on 13 February 2019, each swath has 104 scenes, or pixels, with a footprint size of 17 km x 17 km at nadir. Orbits 6419 and later have 140 scenes across the swath, with a footprint size of 12 km x 17 km. The files are written in the new netCDF version 4 format.