Measurements of N2O by theUARSImproved Stratospheric and Mesospheric Sounder during the Early Northern Winter 1991/92

Abstract

Abstract Measurements of stratospheric nitrous oxide made by the Improved Stratospheric and Mesospheric Sounder (ISAMS) during the period 28 October 1991–18 January 1992 are presented. The data are consistent with the dynamical fields at the time, and are in extremely good qualitative agreement with similar data from the Nimbus-7 SAMS and the Upper Atmosphere Research Satellite (UARS) Cryogenic Limb Array Etalon Spectrometer (CLAES) instruments, although in some regions the values are higher than have been obtained elsewhere. A major problem in the retrieval of the data has been contamination of the measured signal by aerosol emitted during the Mount Pinatubo eruption of June 1991. Despite the uncertainty in the values, the ISAMS N2O measurements provide a unique opportunity to study the synoptic evolution of a long-lived chemical tracer throughout the early winter, with near-continuous high-resolution measurements. The zonally averaged data are shown, as well as the measurements in the Northern Hemispher...