GLOBAL DISTRIBUTION OF BRO AND OCLO BY THE GLOBAL OZONE MONITORING EXPERIMENT, GOME, ON ERS 2.

E. Hegels, P.C. Crutzen, T. Kl
pfel and D. Perner, (Max-Planck-Institut für 
Chemie, Saarstr. 23, D-55122 Mainz, Germany)
J.P. Burrows (Inst. f
r Fernerkundung, Univ. Bremen, Postfach 330440, D-28334 
Bremen)


Gome data are compared with and validated by a number of groundbased 
differential optical spectroscopy DOAS experiments observing zenith scattered 
sunlight at Sndre Strmfjord, SS, Greenland. The ESR2 based Global Ozone 
Monitoring Experiment, GOME, provides UV-VIS-spectra of nadir scattered 
sunlight. The DOAS comparison with solar spectra yields absolute slant columns 
for OClO and BrO besides those for ozone and NO2. 

During July/August 1995 BrO, O3 and NO2 were measured at SS and GOME was 
validated during its overpasses. The validation was continued in January 1996 
when in the presence of the polar vortex OClO columns could be measured in 
addition. Vortex distributions of OClO can be presented now after proper 
validation of the GOME data. Examples for the global distribution of BrO and 
OClO will be given. 

The GOME observations of stratospheric BrO at solar zenith angles of 70x and 
higher in polar regions are unambiguous because the long optical paths give 
rise to strong absorptions. Yet even for the equatorial region with shorter 
optical paths the BrO absorptions could be identified and in average a 
vertical column of (4.0+-1.5)x1013 molec/cm2 was obtained. Taken a uniform 
distribution from 15 Km on this column amounts to 21 ppt BrO in the 
stratosphere. 

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry