SPAIN
1. OBSERVATIONAL ACTIVITIES
The monitoring and research of continuous long term ozone, UV radiation and related atmospheric compounds is mainly conducted by the Meteorological Agency of Spain (AEMET) and the Instituto Nacional de Técnica Aeroespacial (INTA). The Departments of Physics and Meteorology of several Spanish universities also perform long term observations to support their research. There is close cooperation between research and monitoring institutes (INTA/AEMET) and Universities on the field of ozone and UV research, participating together in most of the research (Table I).
Table 1: Spanish Institutes involved in ozone/UV research (R), development (D), modelling (MD), monitoring (MT), and quality assessment/quality control (QA/QC)
1.1Column measurements of ozone and other gases/variables relevant to ozone loss.
The longest total ozone record in Spain (since 1980) has been obtained with the Dobson spectrophotometer #120 installed at "El Arenosillo Atmospheric Sounding Station" (Huelva) and operated by INTA. In 1997 this station is complemented with a Brewer spectrophotometer. The AEMET operates a network of six Brewer spectrophotometers with observations since 1992 at Madrid and Izaña. The Brewer network is calibrated every two years at the RBCC-E campaigns at INTA/El Arenosillo Huelva.
Table 2:Total Ozone Column Operational Long Term measurements in Spain
The Izaña Observatory is one of the reference measurement stations worldwide gathering the most precise ozone measurement instruments: Brewer (since 1992), ozonesondes (since 1993), Pandora (2012), DOAS (1993) and FTIR (1999, the latter in cooperation with the National Institute of Aerospace Technology, INTA, and the Institute for Meteorology and Climate Research, IMK-Germany). These measurements belong to the Global Atmosphere Watch programme (GAW) of the World Meteorological Organization (WMO) and the network of excellence "Network for the Detection of Atmospheric Composition Change (NDACC).
Table 3: Ozone Profile operated by Spain
In the framework of INTA and Dirección Nacional del Antártico (DNA, Argentina) collaboration, three UV-VIS spectrometers were installed at the permanent Argentinean bases of Belgrano (77º 52' S 34º37' W), Marambio (64º 14' S 56º37' W) and Ushuaia (54º 48' S 68º19' W) in 1994. The selected stations are scientifically of interest for Polar atmosphere studies since they cover areas in the stratosphere dynamically and chemically differentiated. The main objective of this network is to provide both long term and near real-time observations of column O3 and NO2, in order to characterize the polar vortex and the O3 destruction. The instruments were updated with new MAXDOAS in the three stations. In Ushuaia, the new MAXDOAS was installed in the GAW station operates by Servicio Meteorológico Nacional (SMN). New instruments have expanded its capability to BrO, OClO, IO and O4.
Table 4: Relevant species related to ozone loss
1.2 Profile measurements of ozone and other gases/variables relevant to ozone loss
In November 1992, the ECC ozonesonde programme was initiated as part of the GAW activity at Izaña Observatory. The ozonesoundings have been launched from Puerto de la Cruz station (36 m.a.s.l.), at a distance of 28 Km from the Izaña Observatory, on a weekly basis and without any interruption since 1992. ECC ozonesondes have been launched on a weekly basis from Madrid by INM since 1992. A long-term ozonesounding programme between INTA and DNA/IAA (Argentina) has been running at the Belgrano station (Argentina, 78oS, 35oW) since 1999.Ozonesondes have been regularly launched throughout the year providing ozone vertically resolved dataset for seasonal characterization of the Antarctic ozone layer. Belgrano ozonesounding station has recently been accepted as NDACC station. AEMET, the Argentinean Meteorological Service (SMN), INTA and the Government of the province of Tierra del Fuego (Argentina), initiated a programme on 2008 for total column atmospheric ozone monitoring from the Ushuaia GAW station. Data from both stations are used to develop the WMO Antarctic ozone bulletin.
FTIR: since February 1999 a ground-based FTIR (Fourier Transform InfraRed) spectrometer (Bruker IFS 120 M) is operated at the Izaña Observatory by the Institut für Meteorologie und Klimaforschung (IMK) (Forschungszentrum Karlsruhe, Germany). Besides zenith column amounts and profile (ZCA) of trace gases such as O3, H2O, HDO, N2O, CH4, HF, HCl, ClONO2, NO, NO2, and HNO3, profiles of gases with narrow absorption lines such as O3, NO, HCl and HF can be retrieved. In March 2005 a new FTIR spectrometer was installed at Izaña Observatory.
Table 4 : Ozone Profile operated by Spain.
1.3UV measurements
The Meteorological Agency of Spain (AEMET) is running a comprehensive ultraviolet ground-based measurement programme which covers all the country. In addition to the operational UV-network of AEMET, autonomous regions of Andalucia, Extremadura, Galicia and Valencia also provide continuous measurements of UVB radiation for research and development purposes (Table 3). These networks are calibrated at the laboratories of AEMET (Madrid Area of Atmospheric Observation Network), which perform a two-year calibration of Broadband detectors of AEMET, and INTA (Huelva, El Arenosillo Sounding Station), which performs the calibration of the INTA/Uex network.
1.4 Calibration activities
In November 2003 the WMO/GAW Regional Calibration Centre for RA-VI region (RBCC-E) was established at the Izaña Atmospheric Research Centre of AEMET, Canary Islands (IZO). RBCC-E owns a full set of calibration and reference-maintenance equipment composed of three Brewer spectroradiometers (The IZO Triad): a Regional Primary Reference (Brewer 157), a Regional Secondary Reference (Brewer 183) and a Regional Travelling Reference (Brewer 185), which can be transported for calibration campaigns outside IZO. The Regional Brewer Calibration Center transfers the calibration from the World Reference Triad in Toronto. Due to the
Table 5: Ultraviolet radiation monitoring network in Spain
doubts about the maintenance of the World Triad, the WMO Scientific Advisory Group for Ozone (WMO-SAG Ozone) authorized RBCC-E in 2011 to transfer its own absolute calibration obtained by Langley.
Brewer inter-comparisons are held annually, alternating between Arosa in Switzerland and El Arenosillo Atmospheric Sounding Station (INTA) in Huelva, in the South of Spain. During these calibration campaigns a total of 45 Brewer ozone spectrometers were calibrated and reported in Huelva 10-20 Jun 2013 (17 instruments), Arosa 14-24 July 2014 (7 instruments) and El Arenosillo May 2015 (21 Instruments).
The calibration reports of the intercomparisons are regularly published as GAW publication series. During this reporting period the Arosa 2012 , Huelva 2013 and Arosa 2014, calibration reports were published (216. Seventh Intercomparison Campaign of the Regional Brewer Calibration Center Europe (RBCC-E), Lichtklimatisches Observatorium, Arosa, Switzerland, 16-27 July 2012, 106 pp. March 2015, 224. Ninth Intercomparison Campaign of the Regional Brewer Calibration Center for Europe (RBCC-E), Lichtklimatisches Observatorium, Arosa, Switzerland, 14-26 July 2014, 40 pp. December 2015, 223. Eighth Intercomparison Campaign of the Regional Brewer Calibration Center for Europe (RBCC-E), El Arenosillo Sounding Station, Huelva, Spain, 10-20 June 2013, 79 pp. December 2015). The last campaign was the XI Regional Brewer Calibration Center for Europe (RBCC-E) intercomparison held at Arosa-Davos Lichtklimatisches Observatorium LKO of MeteoSwiss during the period June 24- July 05, 2016.
In addition to the regular intercomparison campaigns, absolute calibrations were held at Izaña Atmospheric Observatory: the NORDIC campaign in December 2013 supported by ESA CalVal project, and the reference calibration of the Environmental Canada Brewer #145 in March 2014. The last absolute campaign was ATMOZ ozone instruments intercomparison, held at Izaña Atmospheric Observatory (Canary Islands, Tenerife, Spain) from 12-30 September 2016, organised by Izaña Atmospheric Research Centre of the Spanish Meteorological Agency (AEMET) and the World Radiation Center (PMOD-WRC). This campaign was supported by the European Union through the project EMRP 59 ATMOZ, “Traceability for Atmospheric Total Column Ozone.” The objective of the campaign was to compare the Total Ozone measurements of the participating instruments and to obtain a ground-based high-resolution UV range extraterrestrial spectrum.
(More detailed information can be found in Chapter 17 of the Izaña Atmospheric Research Centre (IARC), from the State Meteorological Agency of Spain (AEMET) Activity Report (2012-2014) GAW report 219.)
The INTA ground-based MAXDOAS observations are all contributing to the NDACC and are being certified in this framework. The MAXDOAS instruments have participated to several calibration campaigns, e.g., the recent CINDI2 campaign in Cabaw (NL) in 2016
2. RESULTS FROM OBSERVATIONS AND ANALYSIS
Several studies analyze the ozone evolution and trends of the ozone layer over Spain,(Román et al., 2014)use for the analysis satellites and ERA40,whereas(Mateos et al., 2015). analyse the evolution using ground based Brewer series. There are no significant differences in the trends over the Iberian Peninsula. From the 1970s to the mid-1990s stronger and significant negative trends were observed in the annual series of the averaged Iberian Peninsula: −3.9% per decade whereas the Iberian Peninsula shows a non significant increase from 1995 to 2011. This is in agreement with the ground bases analysis of the period 1991-2012 performed by(Mateos et al., 2015)who found TOC exhibits a positive significant trend in the period 1993–2012 of 9.3 DU per decade at Madrid station.
Figure 1: Temporal Evolution of yearly TOC values at five Spanish Stations (left),(Mateos et al., 2015) and the AEMET UV broadband network.
Thirteen years of ozone soundings at the Antarctic Belgrano II station (78_ S, 34.6_ W) have been analysed to establish a climatology of stratospheric ozone and temperature over the area (Parrondo et al., 2014). Decrease of the total ozone column over Belgrano during spring is highly dependent on the meteorological conditions. Largest depletions (up to 59 %) are reached in coldest years, while warm winters exhibit significantly lower ozone loss (20 %). It has been found that about 11% of the total
O3 loss, in the layer where maximum depletion occurs, takes place before sunlight has arrived, as a result of transport to Belgrano of air from a somewhat lower latitude, near the edge of the polar vortex, providing evidence of mixing inside the vortex.
3. THEORY, MODELLING, AND OTHER OZONE RELATED RESEARCH
A relevant result for this reporting period is the study of the effect of the cross section (XS) on the ozone retrieval of Dobson and Brewer, the reference instruments for the measurement of total ozone. In 2009, the ozone community established the ACSO committee (“Absorption Cross Sections of Ozone”) to review the presently available cross sections (XS) databases and to determine the impact of a change of the reference XS for the different instrument types (ground-based and satellite) used in the individual instrument retrieval algorithms. ( This ACSO committee is a joint commission of Scientific Advisory Group (SAG) of the Global Atmosphere Watch (GAW) of the World Meteorological Organization (WMO) and the International Ozone Commission (IO3C) of the International Association of Meteorology and Atmospheric Sciences (IAMAS).
This study performed with the support of the ESA-CALVAL project was a joint effort of the weather services of Germany, Spain, Switzerland and United States of America with the participation of the Dobson and Brewer WMO calibration centres, which provide the high quality Brewer and Dobson ozone observations together with Bremen University, which provides the new proposed ozone cross section. It was published on ACP in a paper under the title: "Evaluation of the Use of Five Laboratory Determined Ozone Absorption Cross Sections in Brewer and Dobson Retrieval Algorithms”. The paper demonstrates that the use of recently released Ozone Absorption Cross Section by Bremen University solves the historical differences between Dobson and Brewer spectrophotometers, the primary ground-based instruments to measure Total Ozone. The application of this new cross sections to the CEOS Calibration campaign data of reference instruments eliminates the bias between the Ozone measurements of these two instruments, moreover introducing the temperature dependence of the cross section on the retrieval algorithms. The seasonal differences of these instruments also disappear when we apply the Arosa, Switzerland, Dobson and Brewer simultaneous total ozone observations.
Figure 2: Percentage ratio between Dobson (Dobson 64 AD and CD pairs) and Brewer (B#157,B#183 and B#185) when apply the same Langley calibration and different cross section analysed (Bass & Paur , operative (B&P operative) and the temperature quadratic fit (IGACO B&P) , the Daumont, Brion & Malicet (DBM) and the Serdyuchenko 2013 developed by the University of Bremen for the HARMONICS project.(Redondas et al., 2014)
Another relevant study described the main features of the subtropical tropopause region over Tenerife (the Canary Islands, Spain; 28°N, 16°W), examined and characterised using 20-year (1992–2011) ozonesonde data and European Centre for Medium-Range Weather Forecasts ERA-Interim potential vorticity (PV) and zonal wind speed reanalysis.
This study introduces new insights since high-resolution vertical profiles allowed a detailed description of the subtropical tropopause break and the associated subtropical jet stream (STJ), where models fail to properly simulate the upper troposphere–lower stratosphere (UTLS). The subtropical UTLS, which is a rather thick (~8 km) and complex region, is analysed by evaluating four different tropopause definitions: thermal (TT), Cold Point (CPT), ozone (OT), and dynamical (DT) tropopauses. A novel method to determine the DT based on the vertical gradient of Lait’s modified PV is presented. This method represents an analytical improvement for DT determination from model reanalysis. The concept of a second DT and a second OT has been introduced for the first time, showing an excellent agreement with the second thermal tropopause and the cold point tropopauses. The 14.3 km height level is used to differentiate between tropical and extratropical UTLS regimes, intimately linked to the position of the STJ. There is a fairly good consistency between all the defined tropopauses under the double tropopause scheme, except in spring, when the OT is observed at lower levels due to frequent baroclinic instabilities in the upper troposphere. In winter, altitude differences between OT, DT, and TT resulted from poleward STJ excursions forced by blocking systems over the North Atlantic. Analysis of the tropopause inversion layer showed distinctive features for tropical and midlatitude tropopauses.
Figure 3 : Time-height cross section of ozone partial pressure (mPa) and wind speed contours (ms–1) from 8 to 21 km height for (top) multiple and (bottom) single thermal tropopause events. The vertical coordinate is tropopause based. The different tropopause types are shown labeled with their corresponding acronym. TT1, TT2 and TT3 are the first, second and third thermal tropopauses, respectively; DT1 and DT2 are the first and second dynamical tropopause, respectively; OT is the ozone tropopause, and CPT is the Cold-Point tropopause.(Franco et al., 2013)
3.2 Retrieval algorithm developments
Development of inversion algorithms (using the Optimal Estimation Method) for ground-based MAXDOAS remote sensing spectral data, for the retrieval of vertical distributions of the absorbing atmospheric constituents. INTA has recently developed algorithms to implement the Optimal Estimation Method, and therefore allow the retrieval of vertical profile information from the ground-based MAXDOAS spectra, at low vertical resolution for e.g., NO2, O3, BrO.
4.DISSEMINATION OF RESULTS
4.1Information to the public: Database
Total ozone daily means are submitted on a daily basis to the WMO Northern Hemisphere Daily Ozone Mapping Centre run by the Laboratory of Atmospheric Physics at the Aristotle University of Thessaloniki (Greece) and to the WOUDC. Evaluated and refined total ozone data from Madrid, Murcia, El Arenosillo, Santa Cruz de Tenerife and Izaña stations are periodically submitted to the WOUDC database.
AEMET co-leads EBUREWNET European COST action, which aims to facilitate consistent and evenly measurements of ozone, spectral UV, and aerosol optical depth provided by Brewer spectrophotometers deployed in Europe. This project, in which 18 European countries are involved, has been joined by the United States, Canada and Australia. Scientists involved in EUBREWNET work together to increase the characterisation and calibration of instruments, as well as the process and quality control of observations. The database project is hosted by AEMET, where observations are received and processed in real time in a centralised manner. This database gives European response to the demand of organisations such as the World Meteorological Organization, the World Ozone and Ultraviolet Data Centre (WOUDC), the Intergovernmental Panel on Climate Change (IPCC), and the Global Monitoring for Environment and Security (GMES) of the European Union, for monitoring the Earth and atmosphere.
Figure 4 :Spanish Eubrewnet Stations reporting real time ozone and UV observations
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Ozone profiles data over Antarctica are sent to the WMO in almost real time as contribution to the reports on the evolution of the Ozone hole. Web page: ( Information of the INTA Antarctic project for the three stations and disseminated through
4.2Information to the public: UV forecast
The real time ozone and uv observations are disseminated on the web (See Table 1) and the UV index forecast is also available at the AEMET webpage. The AEMET operational UV forecasting system is based on the libradtran software package for radiative transfer calculations [Emde et al., 2016]. The system provides the UVI at noon local time in clear sky conditions for the next five days for the main city of every Spanish province, every island and the cities of Ceuta and Melilla in North Africa. The TOC value is dynamically set from the ECMWF Integrated Forecasting System (IFS) forecasts. AEMET also produces UVI forecast based on the MOCAGE CTM . This model is used operationally at AEMET mainly in order to forecast surface parameters related to air quality, such as NOx, SO2 or O3. However, MOCAGE being a 3D global model, working with 47 vertical hybrid levels covering the PBL, free troposphere and stratosphere, can provide useful information on the evolution of the Total Ozone Column (TOC) distribution around the globe. Hourly forecasts for the Iberian Peninsula and Balearic Islands of NO, NO2, SO2 CO, O3 and TOC are disseminated through the AEMET public webpage. Additionally, MOCAGE provides UVI forecasts on clear sky conditions and considering cloudiness.