Polar Ozone and Aerosol Measurement (POAM) II stratospheric NO₂, 1993–1996

Abstract

Abstract. We describe, for the first time, measurements of stratospheric nitrogen dioxide (NO2) by the Polar Ozone and Aerosol Measurement (POAM II) instrument. Measurements span October 1993 through mid-November 1996 and cover latitude ranges from 55 ø to 72øN and from 63 ø to 88øS. Comparisons with coincident satellite and space shuttle observations show good agreement and confirm the validity of POAM II measurements for scientific investigations. Overall seasonal variations in both hemispheres are qualitatively consistent with standard photochemistry. In the austral late winter/early spring of 1994, however, anomalously high NO2 mixing ratios were observed above 22 km. We conclude that these high NO2 levels resulted from downward transport of NOx-enhanced air from the mesosphere or thermosphere inside the polar vortex. Enhanced NO2 mixing ratios in 1994 were factors of-l.3 and 2.5 larger than at the corresponding times in 1995 and 1996. We conclude that POAM II observations of coincident, localized reductions in ozone of up to 40% were caused by the increased stratospheric NOx via the standard catalytic NO• cycle.

Operational total and tropospheric NO<sub>2</sub> column retrieval for GOME-2

“…This harmonic climatology has been derived from satellite measurements by UARS/HALOE (Gordley et al, 1996) and SPOT-4/POAM-III (Randall et al, 1998) and complementary information from ground-based measurements from the Network for the Detection of Atmospheric Composition Change (NDACC). The stratospheric NO 2 profiles are time dependent and given for 16 latitude bands.…”

Middle atmosphere response to the solar cycle in irradiance and ionizing particle precipitation

“…Following this early work, and Solomon et al ( , 1983 pointed out a coupling mechanism whereby thermospheric NO x could affect the stratosphere. The Halogen Occultation Experiment (HALOE) instrument on the Upper Atmosphere Research Satellite (UARS), and the subsequent Atmospheric Trace Molecule Spectroscopy (AT-MOS) and Polar Ozone and Aerosol Measurement (POAM) experiments provided observational evidence for EPP associated NO x enhancement (Callis et al, 1996;Randall et al, 1998Randall et al, , 2001Rinsland et al, 1996;Russell et al, 1984). However, little effort was devoted to the inclusion of EPP effects in chemistry climate models partly due to complexity and since they were considered to be of secondary importance on climate timescales.…”

Validation of MIPAS-ENVISAT NO<sub>2</sub> operational data

“…The Atmospheric Trace Molecule Spectroscopy experiment (ATMOS) has flown four times on the Space Shuttle between 1985 and 1994 measuring NO 2 in infrared solar occultation (Russell III et al, 1988;Newchurch et al, 1996). The families of the Stratospheric Aerosol and Gas Experiment (SAGE I, II, and III; Chu and McCormick, 1986;Cunnold et al, 1991;NASA LaRC, 2006) and Polar Ozone and Aerosol Measurement (POAM II and III; Randall et al, 1998;Randall et al, 2002) observe NO 2 by solar occultation in the visible while the Halogen Occultation Experiment (HALOE; Russell III et al, 1993) on the Upper Atmosphere Research Satellite (UARS) spacecraft operated in the infrared spectral domain. On the same platform, NO 2 was observed in the infrared by the Improved Stratospheric and Mesospheric Sounder (ISAMS) by means of pressure modulator radiometer technique (Reburn et al, 1996) and by the Cryogenic Limb Array Etalon Spectrometer (CLAES; Dessler et al, 1996).…”