Izaña Atmospheric Observatory as a WMO Centennial Observing Station

Today, supercomputers and sophisticated models and satellites are important tools for climate scientists. However, long-term, high quality continuous observations from thermometers, rain gauges and other instruments remain essential. Without them, we could not be certain that the Earth has warmed by one degree centigrade over the past century. These long-term observations are vital to our scientific understanding of climate variability and change and essential for model and satellite validation activities.

To promote the recovery and continuation of these records, governments are nominating Centennial Observing Stations for formal recognition by WMO. Many Centennial Observation Stations are also of outstanding historical and cultural interest, recalling previous eras and the birth of modern meteorology. Taken together as a network, Centennial Observation Stations are uniquely able to tell the story of recent climatic history.

Izaña Atmospheric Observatory was recognised as a Centennial Observation Station by the WMO in 2017. More information about the WMO Centennial Observing Stations project, can be found here.

Main Scientific Goals

The main goals of the meteorology programme are:

  •   To provide diagnosis and operational weather forecasting to support routine operation activities at the IARC observatories and issue internal severe weather alerts and special forecasts for planned field campaigns, outdoor calibrations, repairs, etc.
  •  To implement and configure High Resolution Numerical Weather Prediction Models capable of capturing the complex meteorology of the mountain observatory, as an aid to improve the supporting forecasts.
  •  To investigate the use of machine learning strategies to improve the forecasting of meteorological and air quality parameters.
  • To maintain meteorological parameter observations according to WMO specifications, and in the framework of AEMET’s Synoptic and Climatological Observation Networks.
  •  To measure conventional meteorological parameters at different stations on the island of Tenerife, to support other observation programmes.
  •  To recover historical meteorological data from various sources to complete the observational data of the Izaña station in the AEMET National Climatological Database (BDCN).
  •   To develop non-conventional meteorological parameters programmes.
  •  To provide meteorological analysis information and technical advice to interpret and support results from other observation programmes and scientific projects, designing and implementing specific algorithms and databases to reach these goals.

Measurement Programme

The Izaña Atmospheric Research Center directly manages six weather observation stations, located at IZO (3), SCO, BTO and TPO.

Izaña Atmospheric Observatory

IZO has three fully automatic weather stations, two of them are located in the weather garden (C430E/60010 and Meteo- STD), which includes a network of five cloud observation webcams, and the third station is on the instrument terrace of the observation tower (Meteo-Tower) at 30 m above ground level. Instrumentation for manual observations (staffed by personnel) with temperature, humidity, pressure and precipitation analog recorders (bands), is also maintained at IZO in order to preserve the historical series that started at Izaña Atmospheric Observatory in 1916.

Santa Cruz Observatory

SCO has a fully automatic weather station located on the instrument terrace.

Botanic Observatory

BTO has a fully automatic weather station installed at the ozonesounding station in the Botanic Garden in Puerto de la Cruz.

Teide Peak Observatory

TPO has an automatic very high altitude weather station with temperature, humidity and pressure sensors, supplemented with data from a wind sensor installed at the Cable Car tower No.4, managed by the Cable car company.

The meteorology programme also has access to meteorological soundings data of pressure, temperature, humidity and wind from the Tenerife station (ID: WMO 60018) located in the town of Güimar. This station belongs to the AEMET upper-air observation network and is managed by the Meteorological Center of Santa Cruz de Tenerife (AEMET).

Meteorological Resources

To accomplish the objectives of the meteorology programme we have the following tools.

LINUX Workstations (Fedora Core) with the Man Computer Interactive Data Access System (McIDAS) application provide access, exploitation and visualization of meteorological information from different geo-referenced observations, modelling and remote sensing (satellite, radar) platforms.

The application provides access to all data in real time in the AEMET National Prediction System, including the following data and products:

  • Global synoptic surface observation and upper-air networks.
  • Outputs of numerical prediction models from ECMWF (IFS) and AEMET (HIRLAM).
  • METEOSAT satellite imagery.
  •  Images of the AEMET Weather Radar Network.
  •  Data from the AEMET Electrical Discharge Detection network.
  •  Products derived from SAF (Satellite Application Facilities) Nowcasting MSG images.

Two different RGB composite images from Meteosat-10 satellite for a dust event on 18/04/2017 08:00 UTC. Left panel: dust (channels 7, 9 and 10), right panel: natural (channels 1, 2 and 3)


Utilising this application different automated processes for the exploitation of meteorological information have been developed, among which we can highlight:

1) Automatic generation of graphical products from specific models and images from derived MSG products (RGB combinations), for consultation through an internal website.

2) Calculation of isentropic back trajectories of air masses from analysis outputs (4 cycles per day) and prediction (every 12 hours and range up to 132 hours) for Tenerife at nine different vertical levels .

3) Lightning strikes in situ detection and AEMET lightning detection network warning system, for taking preventive action to avoid damages in the facilities.

4) Automatic seven day Meteogram generation of temperature, humidity, wind, pressure and clouds for Izaña Observatory using standard isobaric grid points interpolated to 2400 m a.s.l. The statistics have been weighted using the inverse distance to the validity forecast time taking into account the last five available model runs.

EUMETCast receiving system

The EUMETCast real-time receiving system for aerial imagery and meteorological satellite data distributed by EUMETSAT has its own internal web interface for displaying images received, and mass storage system for archiving images of compressed MSG segments in native format.

EUMETSAT Data Center

We have access to the EUMETSAT Data Center for retrieval of images and historical products of Meteosat satellites.

AEMET Server Meteorological Data System

We have access to numerical models databases, observations, bulletins, satellite and radar images is available on the AEMET Server Meteorological Data System (SSDM).

ECMWF products and MARS archive

In addition, we have access to the European Centre for Medium-Range Weather Forecasts (ECMWF) computer systems and consultation of the Meteorological Archival and Retrieval System (MARS), which is the archive of all operational products generated in ECMWF. From this system we have developed different exploitation processes such as:

  •  Routine extraction in two cycles per day of meteorological analysis and prediction fields of the ECMWF IFS model, which are decoded in a compatible format for exploitation from McIDAS and for the integration of the high resolution model.
  •  Monthly extraction of ERA-Interim reanalysis outputs for updating large data series for different projects.
  •  Extraction of previous analysis fields calculation for computing back trajectories with FLEXTRA.
  •  Routine extraction in two cycles per day from Copernicus Atmosphere Monitoring Service (CAMS) system .

AEMET National Climatological Data Base (BDCN)

We have access to the AEMET National Climatological Data Base (BDCN) for data extraction of observations from the AEMET principal and secondary climatological networks.

Meteorological long term records

The series of average temperature, accumulated precipitation, sunshine duration, average relative humidity and average atmospheric pressure at Izaña Atmospheric Observatory have been updated for the years 2017 and 2018.  Additionally, historical meteorological data from various sources were recovered to complete the data series of the Izaña Long-term Observation Station; currently only 0.9% of days remain uncompleted between 1916-2018. This constitutes over a century of meteorological data and is the oldest uninterrupted climate series in the Canary Islands.

In the series of annual mean temperature at IZO, the rate of rise in temperature is maintained at 0.15oC per decade, consistent with the global warming trend. This series is especially relevant since the station is at altitude and is representative of conditions of quasi free troposphere.

The series of annual mean relative humidity (13.16d) continues the downward trend that began after the high values of the second half of the 20th century. The evolution of the annual mean atmospheric pressure (13.16e) remains fairly stable from the beginning of the 21st century, after the multidecadal oscillation seen in the last century.

Time series (1916-2018) of a) annual mean temperature, b) total annual precipitation, c) annual sunshine duration, d) annual mean relative humidity and e) annual mean pressure at Izaña Atmospheric Observatory.


To ensure quality and continuity of observations within national and international meteorological and climatological observation networks in which IARC participates requires constant maintenance and vigilance of meteorological instrumentation and subsequent quality checking of meteorological data from IZO, SCO, BTO and TPO.

The networks in which IARC participates are the Synoptic Observation Network (WMO Region I, ID: 60010), included in the surface observation network of Global Climate Observing System (GCOS), the AEMET Climatological Monitoring Network (ID C430E) and the Baseline Surface Radiation Network (BSRN; station # 61).


Prediction and analysis of severe weather events

Additional activities of the Meteorology programme include prediction and subsequent analysis of severe weather events that may affect operations of the various observation programmes at the four IARC observatories. Special attention is paid to IZO, which is frequently affected by adverse events such as very strong winds, rain and heavy snow, lighting, frost, and frozen rime, which can cause significant damages to facilities.

Relative humidity, temperature, wind velocity and pressure graphics

Outstanding collaborations with other scientific programmes

A collaboration was undertaken with the Tenerife Island Government to study the impact of the temperature, precipitation and clouds on the ecosystem in Las Cañadas del Teide using a year of data collected from the MM5 historical simulations at high resolution.

Seasonal statistics of simultaneous wind speed and cloudiness based on MM5 historical outputs at high resolution, have been included in a report sent to EUMETSAT to assess El Hierro as a potential Satellite Calibration Buoy site.

Various modifications of routines of the FLEXTRA program have been made in order to take into account particle properties. A series of simulations have been made in order to assess the impact on the results in collaboration with the Greenhouse Gases and Carbon Cycle and the Aerosol Groups.

An experiment has been conducted to assess the impact of hourly FLEXTRA output on the capture of specific events from 23 August -1 September 2010 in collaboration with the Aerosols Group.

A database has been designed and created with data from the Canary Islands Government Air Quality observational network and SDS-WAS Multi-Model forecasts interpolated to the air quality network sites. This information will be used in a machine learning strategy project to improve the quality of forecasted PM10 values due to African dust intrusions in conjunction with the Barcelona Supercomputer Centre.

A new index, African Residence Time Index (ARTI), based on FLEXTRA back-trajectories has been designed to distinguish between a high probability of African dust intrusion days and non-dust days at a specific site. This index has been used extensively by various groups in IARC.

We have implemented algorithms to forecast the view angle form the ozone sounding system antenna reception position and the driving balloon, to assure radio coverage during the flight. This software, in conjunction with the ASTRA High Altitude Balloon Flight Planner, was able to increase the rate of successful flights to near 100%. It is routinely used by the Ozone and UV Group.

In situ weather forecasts and specific HYSPLIT and FLEXTRA back-trajectories have been conducted for the MEGEI-MAD campaign carried out in Madrid from 24 September – 7 October 2018, in collaboration with the FTIR Group .

A specialised software has been developed to extract information of regular atmospheric soundings in order to process vertical precipitable water as requested by the Radiation and Water Vapour Groups.

We participated in the Training Course on “Atmospheric Aerosols and Mineral Dust” organized by IARC, held from 20 June – 6 July 2017. We presented a summary of the high resolution tools used by the Meteorology Group in order to improve the Izaña site operational forecasts with special emphasis on the lagrangian trajectories tools used, both FLEXTRA and HYSPLIT, showing in detail the running system configurations.

We participated as co-authors in several presentations of the 9th International Workshop on Sand/Dust Storms and Associated Dustfall, 22-24 May 2018 (for more details see Section 26) and in a presentation in the 11th International Conference on Air Quality – Science and Application, 12-16 March 2018:

  •   Long-term aerosol optical depth (1941-2017) at the Izaña Observatory (García et al., 2018b).
  •   Short-term variations of the Saharan Air Layer atmospheric properties over the North Atlantic driven by NAFDI: Summer 2017 case analysis (Cuevas et al., 2018).
  •   Northern African sources of mineral dust from measurements at the Izaña GAW Observatory (López- Solano, et al., 2018).
  •   High variability of dust composition in the Saharan Air Layer (Rodríguez, et al., 2018).
  •   Air quality trends in a coastal city, Santa Cruz de Tenerife (Milford, et al., 2018).



Cuevas, E., Bustos, J.J., Rodríguez, S., Marrero, C., Reyes, E., García, R.D., García, O.E., Barreto, A. and Guirado-Fuentes, C. Short-term variations of the Saharan Air Layer atmospheric properties over the North Atlantic driven by NAFDI: Summer 2017 case analysis. 9th Internatıonal Workshop on Sand/Dust storms and Assocıated Dustfall, La Laguna, Tenerife, Spain, 22-24 May 2018.

García, O., E. Sepúlveda, J.-A. Morgui, C. Estruch, R. Curcoll, M. Frey, C. Schneider, R. Ramos, C. Torres, S. León, F. Hase, A. Butz, C. Toledano, E. Cuevas, T. Blumenstock, C. Pérez, M. Guevara, J. J. Bustos, and V. Carreño. MEGEI-MAD: Monitoring of Greenhouse Gases Concentrations in Madrid. Integrated Global Greenhouse Gas Information System (IG3IS) Symposium, 13 – 15 November, WMO, Geneva, Switzerland, 2018a.

García, R.D., O.E. García, E. Cuevas and J.J. Bustos, Long-term aerosol optical depth (1941-2017) at the Izaña Observatory. 9th Internatıonal Workshop on Sand/Dust storms and Assocıated Dustfall, La Laguna, Tenerife, Spain, 22-24 May 2018b.

López-Solano, J., Rodríguez, S., Pérez García-Pando, C., Sosa, E., García, M. I., Bustos, J.J., Marrero, C. and Alonso-Pérez, S. Northern African sources of mineral dust from measurements at the Izaña GAW Observatory. 9th Internatıonal Workshop on Sand/Dust storms and Assocıated Dustfall, La Laguna, Tenerife, Spain, 22-24 May 2018.

Milford, C., Cuevas, E., Marrero, C., Bustos, J.J., Torres, C. Air quality trends in a coastal city, Santa Cruz de Tenerife. 11th International Conference on Air Quality – Science and Application, Barcelona, Spain, 12-16 March 2018.

Milford, C., Marrero, C., Martin, C., Bustos, J. & Querol, X. Forecasting the air pollution episode potential in the Canary Islands. Adv. Sci. Res. 2, 21–26, 2008.

Rodríguez, S., Lucarelli, F., Nava, S., García, M.I., López-Solano, J., Marrero, C., Cuevas, E., Prats, N., High variability of dust composition in the Saharan Air Layer. 9th Internatıonal Workshop on Sand/Dust storms and Assocıated Dustfall, La Laguna, Tenerife, Spain, 22-24 May 2018.


Carlos Luis Marrero de la Santa Cruz (AEMET; Head of programme)

Juan José Bustos (AEMET; Research Scientist)

Ramón Ramos (AEMET; Head of Infrastructure, Responsible for Meteorological Observation Programme)

Cándida Hernández (AEMET; Meteorological Observer- GAW Technician)

Concepción Bayo (AEMET; Meteorological Observer- GAW Technician)

Virgilio Carreño (AEMET; Meteorological Observer-GAWTechnician)

Dr Fernando de Ory (AEMET; Meteorological Observer- GAW Technician) left IARC in October 2018

Sergio Afonso (AEMET; Meteorological Observer-GAW Technician)

Dr Emilio Cuevas (AEMET; Research Scientist)

Dr Rosa García (AIR LIQUIDE; Research Scientist)