Multi-year comparison of stratospheric BrO vertical profiles retrieved from SCIAMACHY limb and ground-based UV-visible measurements

F Hendrick,C Hermans,C Fayt,M Van Roozendael,B.-M Sinnhuber,M De Mazière,K Kreher,W Lotz,A Thomas,P V Johnston,A Rozanov,H Bovensmann,J P Burrows,N Theys

doi:10.5194/amt-2-273-2009

Abstract

Abstract. Vertical profiles of stratospheric bromine monoxide (BrO) retrieved daily from ENVISAT/SCIAMACHY (ENVIronmental SATellite/SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) limb scatter data and from ground-based UV-visible observations performed at Harestua (60° N, 11° E), Observatoire de Haute-Provence (44° N, 5.5° E), and Lauder (45° S, 170° E) are compared in the 15–27 km altitude range for the 2002–2006, 2005–2006, and 2002–2005 periods, respectively. At the three stations, the SCIAMACHY and ground-based UV-visible mean profiles agree reasonably well, with relative difference smaller than 23%. When comparing the BrO partial columns, the agreement obtained is good, with mean relative differences smaller than 11% and corresponding standard deviations in the 13–19% range. These comparison results are obtained, however, using different BrO cross sections in SCIAMACHY limb and ground-based UV-visible retrievals. The seasonal variation of the BrO columns at the three stations is consistently captured by both retrievals as well as large BrO column events occurring during the winter and early spring at Harestua which are associated with bromine activation.

Highlights

Owing to their global spatial and temporal coverage, spaceborne sensors are a key component of the global atmosphere observing system, playing a crucial role for understanding and monitoring climate change and ozone depletion
We present the results of the first multi-year comparison exercise of bromine monoxide (BrO) vertical distributions retrieved from SCIAMACHY limb measurements (version 3.2 of the scientific product from the Institute of Environmental Physics (IUP/IFE) at the University of Bremen) and ground-based zenith-sky UV-visible observations
The quality of the retrieval is lower, mainly because the solar zenith angle (SZA) range corresponding to the BrO differential slant column densities (DSCDs) is smaller (SZA at local noon can reach 84◦ at 60◦ N) and the information content is somewhat lower than it is for the rest of the year (Hendrick et al, 2007)

Summary

Introduction

Owing to their global spatial and temporal coverage, spaceborne sensors are a key component of the global atmosphere observing system, playing a crucial role for understanding and monitoring climate change and ozone depletion. We present the results of the first multi-year comparison exercise of BrO vertical distributions retrieved from SCIAMACHY limb measurements (version 3.2 of the scientific product from the Institute of Environmental Physics (IUP/IFE) at the University of Bremen) and ground-based zenith-sky UV-visible observations. Stratospheric BrO profiles and corresponding partial columns retrieved from ground-based UV-visible measurements at Harestua, OHP, and Lauder are compared to coincident SCIAMACHY limb data. At Lauder, we found 517 morning coincidences for the September 2002–October 2005 period

OHP and Lauder

Harestua

Findings

Conclusions