Ozone profile retrieval from limb scatter measurements in the HARTLEY bands: further retrieval details and profile comparisons

G J Rohen,M Sinnhuber,T Steck,E J Llewellyn,M Palm,C V Savigny,M López-Puertas,H Winkler,L Froidevaux,J P Burrows,H Bovensmann,J W Kaiser

doi:10.5194/acp-8-2509-2008

G J Rohen, M Sinnhuber + Show 10 more

Open Access

https://doi.org/10.5194/acp-8-2509-2008

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Abstract

Abstract. SCIAMACHY limb scatter radiance measurements at selected wavelengths in the HARTLEY bands have been used to retrieve ozone profiles in the upper stratosphere and lower mesosphere. Comparisons with profiles measured by a ground based radiometer in Norway, MIPAS on board ENVISAT, HALOE on UARS and MLS on AURA indicate an agreement within 15% between 40 and 55 km and show that the retrieval provides reliable ozone profiles at these altitudes. Above 55 km, an increasing overestimation is observed. Beside the profile comparisons, further retrieval features of the current retrieval (version 1.26) are described.

Highlights

Mesospheric ozone profiles are of interest, e.g. for investigations of Sun-Earth interactions like SPE s (Rohen et al, 2005) or of solar cycle effects
This paper provides further details on the retrieval algorithms and shows comparisons with profiles from a ground based radiometer, MIPAS on board ENVISAT, HALogen Occultation Experiment (HALOE) on Upper Atmosphere Research Satellite (UARS) and Microwave Limb Sounder (MLS) on AURA
The inversion technique applied to Solar Mesosphere Explorer (SME) measurements, up to now the only successful ozone retrieval from satellite-borne limb limb scatter measurements in the UV-B, exploits radiances at 265 and 296.4 nm (Rusch et al, 1983); ozone profile retrievals at wavelengths in the HARTLEY bands from SOLSE observations (McPeters et al, 2000) have been done using this method, but had difficulties due to a low signal-to-noise ratio

Summary

Introduction

Mesospheric ozone profiles are of interest, e.g. for investigations of Sun-Earth interactions like SPE s (Rohen et al, 2005) or of solar cycle effects. They are required for modeling atmospheric dynamics, e.g. for climate forecasts. For the spectral range used in this study only a single detector read-out is performed at each tangent height step leading to an across-track spatial resolution of 960 km. One single vertical limb scan takes 60 s Within this period of time ENVISAT moves about 447 km. The tangent point moves towards the spacecraft during an upward scan This effect corresponds to a horizontal distance. The first channel covers the lowest spectral region up to 314 nm with a spectral resolution of 0.21 nm whose measurements are used for this presented retrieval

Retrieval methodology and algorithm

Profile comparisons

Findings

Conclusions