Comparison of TROPOMI Calibration to the Calibration of S-NPP OMPS

The near co-location of measurements from S-5P and S-NPP allow for intercomparison between the calibrations of instruments onboard each satellite. We have used measurements from the Ozone Mapping and Profiler Suite (OMPS) sensor, whose calibration is well known and documented, to investigate the calibration of TROPOMI. Our analysis of ice radiance measurements indicate a large error in solar-normalized TROPOMI radiances (up to 6%) that increases with decreasing wavelength. Further analysis shows the error to be related to the solar flux, and not the radiance, measurements from the sensor. We also show wavelength inconsistencies between radiance and solar flux measurements between 0.01 and 0.03 nm that need to be corrected before accurate sun-normalized radiances can be used. In this presentation we will describe our analytical techniques and provide more details on these results.