The 4th Regional Brewer Calibration Center for Europe (RBCC-E) intercomparison
The 4th Regional Brewer Calibration Center for Europe (RBCC-E) intercomparison
The 4th Regional Brewer Calibration Center for Europe (RBCC-E) intercomparison was held at El Arenosillo Atmospheric Sounding Station of the National Institute for Aerospace Technology (INTA) during the period September 7-17, 2009.The 4th campaign has been a joint exercise of the Regional Dobson Calibration Center for Europe (RDCC-E) and the RBCC-E, in collaboration with the Area of Instrumentation and Atmospheric Research of INTA, and with the support of the World Meteorological Organization (WMO) Global Atmospheric Watch (GAW) program and the European Space Agency (ESA) CEOS-CalVal project.
This campaigns hosted 17 Brewers, 5 Dobsons, 2 Benthams, 3 DOAS type instruments and ozone sondes managed by more than 30 scientists from Africa, Asia, America and Europe (see participant list).
The 17 Brewer spectrophotometers from Spain (7), UK (2), Canada (2), Morocco (2), China (1), The Netherlands (1) and Switzerland (1) has been calibrated for ozone against the RBCC-E reference maintained at the Izaña Atmospheric Research Centre of Meteorological State Agency of Spain (AEMET). The Dobsons from Germany, Spain, Denmark and Russia (2) has been calibrated against the European Dobson reference managed by the Meteorological Observatory of Hohenpeissenberg of the German Weather Service (DWD). In addition, the QASUME unit European Reference for spectral UV radiation, managed by the World Radiation Center, provided the UV reference to the instruments.
The campaign was scheduled in four phases. In the first two days the instruments were compared against the reference without previous modifications. After that, maintenance activities, provided by International Ozone Services (IOS; Canada), was performed in some Brewers. The Third phase consisted in a blind comparison using the RBCC-E travelling instrument as ozone reference, and the QASUME unit as UV reference. The fourth phase of the campaign was dedicated to Brewer-Dobson reference s intercomparison for total ozone and Umkehr (ozone profiles with inversion method). The Umkehr profiles were validated with ozone vertical profiles from ECC ozone sondes launched by the Area of Instrumentation and Atmospheric Research of INTA.
Very preliminary results are very promising. A good agreement in total column ozone measurements is observed. A 70% of the Brewers (12 of a total of 17 Brewers) agree the reference (RBCC-E traveling reference Brewer#185) within +/-1% as it is shown in the figure.
Brewer spectrophotometers on the roof of the El Arenosillo Atmospheric Sounding Station (National Institute for Aerospace Technology –INTA-). September 2009.
Participants in the 4th Regional Brewer Calibration Center for Europe (RBCC-E) intercomparison.
