Thirteenth Intercomparison Campaign of the Regional Brewer Calibration Center Europe: Lichtklimatisches Observatorium, Arosa, Switzerland: 30 July–10 August 2018

Editado por Alberto Redondas y Stoyka NetchevaThis thirteenth campaign was a joint exercise of the Regional Brewer Calibration Center for Europe (RBCC-E) and the Regional Dobson Calibration Center (RDCC-E) with the support of MeteoSwiss and of the Global Atmosphere Watch (GAW) Programme of the World Meteorological Organization (WMO). The following operations were performed by the RBCC-E during the intercomparison: Ozone calibration against the RBCC-E travelling reference (B#185) ; Compilation of the calibration histories of the instruments ; Evaluation of the Level 2 Eubrewnet ozone data for the period between intercomparisons

Calibración a nivel de Hardware de un detector Cherenkov de agua (Chitaga) en el arreglo GUANE para estudios de clima espacial

Water Cherenkov Detectors (WCDs) play an essential role in space weather and cosmic rays studies around the world. In this article, we present a general methodology to calibrate a WCD based finding its optimum operation point and counting the delay time of the transmission cables. The dynode charge histogram of the WCD and CORSIKA simulations validate this methodology. Finally, to illustrate the capability of WCD tomeasure fluctuations in the secondary CR flux, we studied the 07.09.2017 Forbush and compared our measurements with data obtained from the Neutron Flux Monitor at UNAM and the Kyoto Dst index service.Los detectores Cherenkov de agua (WCD, por sus siglas en inglés) desempeñan un papel esencial en el estudio del clima espacial y los rayos cósmicos en todo el mundo. En este artículo, presentamos una metodología general para calibrar un WCD basado en encontrar su punto de operación óptimo y contarel tiempo de retardo de los cables de transmisión. El histograma de carga de dinodos de las simulaciones WCD y CORSIKA valida esta metodología. Finalmente, para ilustrar la capacidad de WCD para medir las fluctuaciones en el flujo de CR secundario, estudiamos el Forbush ocuurido el dia 07.09.2017 y comparamosnuestras mediciones con los datos obtenidos del Monitor de flujo de neutrones en la UNAM y el servicio de índice Dst de Kyoto

Calibración a nivel de Hardware de un detector Cherenkov de agua (Chitaga) en el arreglo GUANE para estudios de clima espacial

Water Cherenkov Detectors (WCDs) play an essential role in space weather and cosmic rays studies around the world. In this article, we present a general methodology to calibrate a WCD based finding its optimum operation point and counting the delay time of the transmission cables. The dynode charge histogram of the WCD and CORSIKA simulations validate this methodology. Finally, to illustrate the capability of WCD tomeasure fluctuations in the secondary CR flux, we studied the 07.09.2017 Forbush and compared our measurements with data obtained from the Neutron Flux Monitor at UNAM and the Kyoto Dst index service.Los detectores Cherenkov de agua (WCD, por sus siglas en inglés) desempeñan un papel esencial en el estudio del clima espacial y los rayos cósmicos en todo el mundo. En este artículo, presentamos una metodología general para calibrar un WCD basado en encontrar su punto de operación óptimo y contarel tiempo de retardo de los cables de transmisión. El histograma de carga de dinodos de las simulaciones WCD y CORSIKA valida esta metodología. Finalmente, para ilustrar la capacidad de WCD para medir las fluctuaciones en el flujo de CR secundario, estudiamos el Forbush ocuurido el dia 07.09.2017 y comparamosnuestras mediciones con los datos obtenidos del Monitor de flujo de neutrones en la UNAM y el servicio de índice Dst de Kyoto

Twelfth Intercomparison Campaign of the Regional Brewer Calibration Center Europe: El Arenosillo Atmospheric Sounding Station, Huelva, Spain, 29 May to 9 June 2017

Editado por Alberto Redondas y Stoyka NetchevaThe twelfth European Brewer Intercomparison Campaign was organized by the Regional Brewer Calibration Center for Europe (RBCC-E) in collaboration with the “Area of Instrumentation and Atmospheric Research Area” of Instituto Nacional de Tecnica Aeroespacial (INTA), with the support of the Global Atmosphere Watch (GAW) Programme of the World Meteorological Organization (WMO) and the EUBREWNET ES1207 COST Action. Alongside the campaign, the ATMOZ (Traceability of Atmospheric Total Ozone) project workshop took place at the station. In addition, this event was also used as a demonstration exercise of the calibration methodologies and error assessment developed by the project (Gröbner et al., 2018)

Wavelength calibration of Brewer spectrophotometer using a tunable pulsed laser and implications to the Brewer ozone retrieval

In this contribution we present the wavelength calibration of the travelling reference Brewer spectrometer of the Regional Brewer Calibration Center for Europe (RBCCE) at PTB in Braunschweig, Germany. The wavelength calibration is needed for the calculation of the ozone absorption coefficients used by the Brewer ozone algorithm. In order to validate the standard procedure for determining Brewer’s wavelength scale, a calibration has been performed by using a tunable laser source at PTB in the framework of the EMRP project ENV59 ATMOZ “Traceability for the total column ozone”. Here we compare these results to those of the standard procedure for the wavelength calibration of the Brewer instrument. Such a comparison allows validating the standard methodology used for measuring the ozone absorption coefficient with respect to several assumptions. The results of the laser-based calibrations reproduces those obtained by the standard operational methodology and shows that there is an underestimation of 0.8 % of the ozone absorption coefficients due to the use of the parametrized slit functions.This work has been supported by the European Metrology Research Programme (EMRP) within the joint research project ENV59 “Traceability for atmospheric total column ozone” (ATMOZ). The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union

Brewer-OMI validation

Presentación realizada en: Brewer Ozone Spectrophotometer/Metrology Open Workshop, celebrado en Ponta Delgada (Sao Miguel, Azores) del 17 al 20 de mayo de 2016

EUBREWNET Updates

Presentación realizada en: Nordic Ozone Group Meeting (2021), celebrado el 21 de abril de 2021 de manera virtual

RBCC-E Triad

Comunicación presentada en: Brewer Ozone Spectrophotometer/Metrology Open Workshop celebrado del 17 al 20 de mayo de 2016 en Ponta Delgada, Azores, Portugal

Internal consistency of the Regional Brewer Calibration Centre for Europe triad during the period 2005–2016

Total ozone column measurements can be made using Brewer spectrophotometers, which are calibrated periodically in intercomparison campaigns with respect to a reference instrument. In 2003, the Regional Brewer Calibration Centre for Europe (RBCC-E) was established at the Izaña Atmospheric Research Center (Canary Islands, Spain), and since 2011 the RBCC-E has transferred its calibration based on the Langley method using travelling standard(s) that are wholly and independently calibrated at Izaña. This work is focused on reporting the consistency of the measurements of the RBCC-E triad (Brewer instruments #157, #183 and #185) made at the Izaña Atmospheric Observatory during the period 2005–2016. In order to study the long-term precision of the RBCC-E triad, it must be taken into account that each Brewer takes a large number of measurements every day and, hence, it becomes necessary to calculate a representative value of all of them. This value was calculated from two different methods previously used to study the long-term behaviour of the world reference triad (Toronto triad) and Arosa triad. Applying their procedures to the data from the RBCC-E triad allows the comparison of the three instruments. In daily averages, applying the procedure used for the world reference triad, the RBCC-E triad presents a relative standard deviation equal to σ = 0.41%, which is calculated as the mean of the individual values for each Brewer (σ157 = 0.362%, σ183 = 0.453% and σ185 = 0.428%). Alternatively, using the procedure used to analyse the Arosa triad, the RBCC-E presents a relative standard deviation of about σ = 0.5%. In monthly averages, the method used for the data from the world reference triad gives a relative standard deviation mean equal to σ = 0.3% (σ157 = 0.33%, σ183 = 0.34% and σ185 = 0.23%). However, the procedure of the Arosa triad gives monthly values of σ = 0.5%. In this work, two ozone data sets are analysed: the first includes all the ozone measurements available, while the second only includes the simultaneous measurements of all three instruments. Furthermore, this paper also describes the Langley method used to determine the extraterrestrial constant (ETC) for the RBCC-E triad, the necessary first step toward accurate ozone calculation. Finally, the short-term or intraday consistency is also studied to identify the effect of the solar zenith angle on the precision of the RBCC-E triad.This work has been supported by the European Metrology Research Programme (EMRP) within the joint research project ENV59 “Traceability for atmospheric total column ozone” (ATMOZ)

Brewer-OMI validation: a brief tutorial

Presentación realizada en: Brewer Ozone Spectrophotometer/Metrology Open Workshop, celebrado en Ponta Delgada (Sao Miguel, Azores) del 17 al 20 de mayo de 2016