Performance of the Spanish Brewer Network assessed using satellite data from TOMS, GOME, OMI and GOME-2 instruments
Manuel Anton(1), Maria Lopez(2), Jose Manuel Vilaplana(3), Diego Loyola(4), Mark Kroon(5), Rich McPeters(6), Antonio Serrano(1), Manuel Bañon(2) and Benito de la Morena(3)
(1) Universidad de Extremadura, Avd. de Elvas, s/n, 06071 Badajoz, Spain
(2) Agencia Estatal de Meteorologia, , Madrid, Spain
(3) INTA, , El Arenosillo, Spain
(4) DLR, , Wessling, Germany
(5) KNMI, , De Blit, Netherlands
(6) NASA, , Greenbelt, United States
With the most advanced atmospheric models predicting global ozone recovery by no earlier than 2075, it is of great scientific and societal importance to maintain a global long-term record of accurate ozone measurements. Here satellite remote sensing observations complement ground-based measurements, providing global daily maps with uniform spatial coverage by using a single satellite instrument. To ensure quality, the comparison of satellite ozone data products with reliable ground-based ozone measurements is a crucial activity. In addition, satellite ozone data can be used to quantify the performance of the ground-based network, since notable changes for individual stations in the ground-satellite differences are usually related to problems in ground-based records. In this framework, the main objective of this work is to analyze the total ozone column measurements from five Brewer spectroradiometers in the Iberian Peninsula using the following satellite instruments: Total Ozone Mapping Spectrometer (TOMS/Earth-Probe), Ozone Monitoring Instrument (OMI/EOS-Aura) and Global Ozone Monitoring Experiment (GOME/ERS-2 and GOME-2/MetOp).
The Spanish Agency of Meteorology (AEMet) has accumulated nearly twenty years of experience in measuring total ozone column measurements with Brewer spectroradiometers. The Spanish Brewer Network consists of seven Brewer instruments located on the Iberian Peninsula and the Canary Islands. The ground-based stations used in this study are from north to south: Coruña (43.33ºN, 8.42ºW), Zaragoza (41.01ºN, 1.01ºW), Madrid (40.45ºN, 3.72ºW), Murcia (38.03ºN, 1.17ºW) and El Arenosillo (37.06ºN, 6.44ºW). The Brewer instrument at El Arenosillo belongs to the Spanish Institute for Aerospace Technology (INTA). These five Brewer instruments were installed between 1992 and 2000 and are biannually calibrated by comparison with the travelling references Brewer #017 from the International Ozone Services (IOS) and Brewer #150 from the Regional Brewer Caclibration Centre – Europe (RBCC-E). Comparisons with the travelling reference Brewer instruments confirm the reliability of the Spanish Brewer calibration.
Based on our findings we conclude that the agreement of the Spanish Brewer Network with satellite data is excellent. However, total ozone column data from satellite and ground-based instruments shows small but systematic differences which are attributed to several factors such as: geometric observational and instrumental differences between satellite and ground-based techniques, and the absolute accuracy of the satellite observations and ground-based measurements. Here we quantify these factors and provide quantitative estimates on the Performance of the Spanish Brewer Network assessed using satellite data