The Brewer MkIII Spectrophotometer is specifically designed to provide high accuracy measurement of spectrally resolved UV in the range of 295-365nm for climatology monitoring and public health to international standards. It is also capable of providing total ozone and SO2 column measurements for long term monitoring of climatological and public safety impacts of these trace gases. The Brewer is the standard instrument used in the World Meteorological Organization ozone monitoring network.
In measurements of total column of trace gases, the sun is assumed as a constant source, hence by comparing the measured UV spectrum with the known solar output, and modelling the scattering properties of the atmosphere, concentration as a function of height can be deduced up to a height of 50Km.
Further information about the Brewer and a specifications sheet here.
Use at The University of Manchester
The Brewer instrument at The University of Manchester has been in operation since summer 2000. It was recalibrated in 2002 and was found to be within 0.5 DU of the standard spectrophotometer.
Data from the instrument has been supplied to other organizations for the purpose of monitoring low ozone events and arrangements are in place to contribute to the database at World Ozone and UV Data Center (WOUDC), Canada.
The figure below shows a comparison between the Manchester Brewer and the TOMS flyover at Sibton. The correlation stands at 85% which is reasonable given the distance and the overall average O3 value differs by about -1%.
The Brewer Spectrophotometer is supported by the NCAS Facility for Ground-based Atmospheric Measurement (FGAM).