During the 2003 SAGE (Stratospheric Aerosol and Gas Experiment) III Ozone Loss and Validation Exper-iment (SOLVE) II, the fourteen-channel NASA Ames Air-borne Tracking Sunphotometer (AATS-14) was mounted on the NASA DC-8 aircraft and measured spectra of total and aerosol optical depth (TOD and AOD) during the sunlit por-tions of eight science flights. Values of ozone column con-tent above the aircraft have been derived from the AATS-14 measurements by using a linear least squares method that exploits the differential ozone absorption in the seven AATS-14 channels located within the Chappuis band. We compare AATS-14 columnar ozone retrievals with tempo-rally and spatially near-coincident measurements acquired by the SAGE III and the Polar Ozone and Aerosol Measure-ment (POAM) III satellite sensors during four solar occulta-tion events observed by each satellite. RMS differences are 19 DU (7% of the AATS value) for AATS-SAGE and 10 DU (3% of the AATS value) for AATS-POAM. In these checks of consistency between AATS-14 and SAGE III or POAM III Correspondence to: J. M. Livingston (jlivingston@mail.arc.nasa.gov) ozone results, the AATS-14 analyses use airmass factors de-rived from the relative vertical profiles of ozone and aerosol extinction obtained by SAGE III or POAM III. We also compare AATS-14 ozone retrievals for measure-ments obtained during three DC-8 flights that included ex-tended horizontal transects with total column ozone data ac-quired by the Total Ozone Mapping Spectrometer (TOMS) and the Global Ozone Monitoring Experiment (GOME) satellite sensors. To enable these comparisons, the amount of ozone in the column below the aircraft is estimated either by assuming a climatological model or by combining SAGE and/or POAM data with high resolution in-situ ozone mea-surements acquired by the NASA Langley Research Center chemiluminescent ozone sensor, FASTOZ, during the air-craft vertical profile at the start or end of each flight. Re-sultant total column ozone values agree with correspond-ing TOMS and GOME measurements to within 10–15 DU (∼3%) for AATS data acquired during two flights – a lon-gitudinal transect from Sweden to Greenland on 21 January, and a latitudinal transect from 47 • N to 35 • N on 6 Febru-ary. For the round trip DC-8 latitudinal transect between © 2005 Author(s). This work is licensed under a Creative Commons License. 2036 J. M. Livingston et al.: Retrieval of ozone column content from airborne Sun photometer 34 • N and 22 • N on 19–20 December 2002, resultant AATS-14 ozone retrievals plus below-aircraft ozone estimates yield a latitudinal gradient that is similar in shape to that observed by TOMS and GOME, but resultant AATS values exceed the corresponding satellite values by up to 30 DU at certain lat-itudes. These differences are unexplained, but they are at-tributed to spatial and temporal variability that was associ-ated with the dynamics near the subtropical jet but was unre-solved by the satellite sensors. For selected cases, we also compare AATS-14 ozone re-trievals with values derived from coincident measurements by the other two DC-8 based solar occultation instruments: the National Center for Atmospheric Research Direct beam Irradiance Airborne Spectrometer (DIAS) and the NASA Langley Research Center Gas and Aerosol Monitoring Sys-tem (GAMS). AATS and DIAS retrievals agree to within RMS differences of 1% of the AATS values for the 21 Jan-uary and 19–20 December flights, and 2.3% for the 6 Febru-ary flight. Corresponding AATS-GAMS RMS differences are ∼1.5% for the 21 January flight; GAMS data were not compared for the 6 February flight and were not available for the 19–20 December flight. Line of sight ozone retrievals from coincident measurements obtained by the three DC-8 solar occultation instruments during the SAGE III solar oc-cultation event on 24 January yield RMS differences of 2.1% for AATS-DIAS and 0.5% for AATS-GAMS.