Ozone Comparison between Pandora #34, Dobson #061, OMI, and OMPS at Boulder Colorado for the period December 2013–December 2016

A co-located Pandora Spectrometer Instrument (Pan #034) has been compared to a well calibrated Dobson spectroradiometer (Dobson #061) in Boulder, Colorado and with two satellite instruments over a 3-year period. The results show good agreement between Pan#034 and Dobson #061 within their statistical uncertainties after both records are corrected for ozone retrieval sensitivity to stratospheric temperature variability obtained from the Global Modeling Initiative (GMI) and Modern-Era Retrospective analysis for Research and Applications (MERRA2) model calculations. Pandora#034 and Dobson#061 differ by an average of 2.2 % when both instruments use their standard ozone absorption cross sections in the retrievals algorithms. The results demonstrate the stability of Pandora observations against NOAA Dobson in Boulder, CO over a three year period of continuous operation. The relative drift between two systems is 0.6 % per year.