Validation of total ozone column derived from OMPS using ground-based spectroradiometer measurements

Abstract

The total ozone column (TOC) observations derived from the Ozone Mapping and Profiler Suit (OMPS) on-board the Suomi National Polar-orbiting Partnership (Suomi NPP) spacecraft were recently released for monitoring ozone in the stratosphere. Two kinds of TOC data which are derived using the NPOESS algorithm (OMPS-NPOESS) and the TOMS Version 7 algorithm (OMPS-TOMS) are provided. So far, few studies have been conducted to validate the accuracy of the OMPS TOC data. In this letter, we validate a 1 year OMPS-derived TOC data set (from March 2012 to February 2013) by comparing them with ground-based spectroradiometer data. We also examine the difference of the data derived using OMPS-NPOESS and OMPS-TOMS algorithms. Our results show a moderate correlation between OMPS-derived TOC and ground-based data, and the average relative difference between the two data sets (OMPS data minus the ground-based data) is negative, which indicates an underestimation of the TOC in the OMPS data. Such relative difference is not globally consistent: smaller values (around –10% to 0%) are found in low latitudinal areas (from 30° S to 30° N), whereas comparatively larger differences (around –25% to –15%) are detected in data on the mid-high latitudinal areas. A comparison of the two different algorithms suggests that the OMPS-TOMS-derived data have a generally better accuracy than those from OMPS-NPOESS.