Intercomparison of ozone measurements in the lower stratosphere from the UARS Halogen Occultation Experiment and the ER‐2 UV absorption photometer

Ozone data obtained by the Halogen Occultation Experiment (HALOE) on the NASA Upper Atmosphere Research Satellite (UARS) have been compared with ozone data obtained by the NOAA dual-beam, UV absorption photometer on the NASA ER-2 aircraft during the 1994 Airborne Southern Hemisphere Ozone Experiment/Measurements for Assessing the Effects of Stratospheric Aircraft (ASHOE/MAESA) campaign. This paper describes the measurement characteristics of the two instruments and the precision and accuracy of the two data sets. A total of 26 cases are discussed in which the two different measurements occur within 24 hours, 2.5° latitude, and 10° longitude of each other. Generally, agreement between the two data sets improved the closer in time and space the two measurements occurred. The agreement was better than 10% at ER-2 cruise altitudes (∼50–70 mbar) where the error estimated for HALOE is slightly larger than 18%.