Atmospheric carbon dioxide (night-time daily mean mixing ratio) measured at Izaña Observatory since 1984 and derived interannual trend. Superposed to a continuously growing interannual trend (due to anthropogenic emissions), there is a seasonal cycle (net biomass increase in the northern hemisphere spring and summer, and its associated atmospheric carbon dioxide decrease; and net biomass decrease in the northern hemisphere autumn and winter; and its associated atmospheric carbon dioxide increase).
Anthropogenic greenhouse gases increase is the major driver of the present and forthcoming climate change. IARC carries out high quality atmospheric greenhouse gases measurements at Izaña observatory (Global GAW station), following WMO GAW recommendations.
To achieve the high quality required for the measurements, IARC has built measurement systems (hardware based on commercial components; acquisition, control, and raw data processing software done by IARC staff) that work in a non-commercial way (achieving much better accuracy). The measurement systems are continuously calibrated (every 15 minutes or 60 minutes depending on the particular system) using working standards. The working standards are calibrated against the Izaña standards (provided by the WMO GAW Central Calibration Laboratory) every two weeks. Therefore, the measurements are in the WMO scale, and the working standards are traceable to the WMO GAW primary standards.
IARC Greenhouse Gases and Carbon Cycle program deals with the measurement of the main greenhouse gases, but also with carbon monoxide measured with a GC-RGA3 due to: a) the measurement scheme (gas chromatography, and the use of working standards and Izaña standards) is similar to that used with some greenhouse gases, b) carbon monoxide affects the atmospheric burden of methane.
The paper titled “A statistical approach to quantify uncertainty in carbon monoxide measurements at the Izaña global GAW station: 2008–2011” has been published in the scientific journal “Atmospheric Measurement Techniques”
The two general ambient air inlets which provide ambient air for all instruments that analyse it, are 8cm inner diameter (ID) stainless steel pipes, and have a high flow rate. These inlets are situated on top of the building tower; the height above the ground has changed through the years: 13 m (1984-2000), 8 m (2000- May 2005) and 30 m (from June 2005). The measurement systems for greenhouse gases and carbon monoxide are located in two laboratories on the third floor of the Izaña Observatory tower.
Carbon Dioxide (measured in-situ continuously since 1984 with NDIR analysers)
The main part of the measurement system is a NDIR analyser (Siemens Ultramat 3 from 1984 to 2006; LI-COR Li-7000 from 2007 till present, working simultaneously with a LI-COR Li-6252 from 2008 till present). Upstream of the NDIR, a cryocool trap is used to reduce the dew point of ambient air to -65 C.
Between calibrations, ambient air is analysed continuously and raw data are stored. Physical data are obtained using the instrument calibrations performed using 3 working standards.
Methane (measured in-situ continuously since 1984 with a GC-FID)
The main part of the measurement system is a gas chromatograph GC-3800 DANI with a flame ionization detector (FID). Upstream of the GC sample loop (10 ml size), a cryocool trap is used to reduce the dew point of ambient air to -65 C. The instrument is calibrated every 30 minutes using a working gas tank (at minutes 15 and 45 every hour). The working gas tank is calibrated every two weeks against the methane Izana standards (provided by WMO GAW CH4 CCL). Four samples are automatically measured every hour: at 00 and 30 minutes the sample is ambient air, at 15 and 45 minutes the sample is working gas. Physical data for each ambient air injection are obtained using the two bracketing instrument calibrations (injections of working gas).
Nitrous Oxide and Sulphur Hexafluoride (measured in-situ continuously since 2007 with a GC-ECD)
Carbon Monoxide (measured in-situ continuously since 2008 with a GC-RGA3)
Click here to download a paper containing more information about the instrument and the measurements carried out
Collaborative Measurement Programmes
Since 1991, IARC collects weekly ambient air in a pair of flasks for the NOAA/ESRL/GMD CCGG Cooperative Air Sampling Network. NOAA/ESRL/GMD/CCGG analyses in these samples the mixing ratio of carbon dioxide (and its stable isotope ratios), methane, carbon monoxide, hydrogen, nitrous oxide, sulphur hexafluoride, and recently, some more trace gases.
Since 1984, IARC collects carbon dioxide samples (using a sodium hydroxide solution) for the Carbon Cycle Group, Institut für Umweltphysik, University of Heidelberg. They analyse such samples for the radioactive isotope carbon 14.
After processing and quality controlling, IARC greenhouse gases data are submitted to the WMO GAW World Data Center for Greenhouse Gases (WDCGG).
IARC contributes to the computation of the CO2 surface fluxes carried out by the Max-Planck Institute of Jena, those carried out by NOAA (CarbonTracker) and those carried out by the Wageningen University (CarbonTracker Europe).
IARC contributes to the computation of CO2 global distribution that carries out the Japan Meteorological Agency using an inversion model.
Methane, Carbon Monoxide, Nitrous Oxide and Carbon Dioxide Audit (EMPA, September 2013) (download pdf)
Methane and Carbon monoxide Audit (EMPA, March 2009) (download pdf)
Nitrous Oxide Audit (Dr Eckhart Scheel, WCC-N2O, November 2008) (download pdf)
Methane and Carbon monoxide Audit (EMPA, December 2004) (download pdf)
Dalsøren, S. B., Myhre, C. L., Myhre, G., Gomez-Pelaez, A. J., Søvde, O. A., Isaksen, I. S. A., Weiss, R. F., and Harth, C. M.: Atmospheric methane evolution the last 40 years, Atmos. Chem. Phys. Discuss., 15, 30895-30957, doi:10.5194/acpd-15-30895-2015, 2015 . (Link to the paper)
Gomez-Pelaez, A.J., R. Ramos, V. Gomez-Trueba, R. Campo-Hernandez, E. Reyes-Sanchez: "GGMT-2015 Izaña station update: instrumental and processing software developments, scale updates, aircraft campaign, and plumbing design for CRDS" to be published in the GAW report of the "18th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases, and Related Measurement Techniques (GGMT) (La Jolla, California, USA, September 13-17, 2015)", World Meteorological Organization (Link to the paper).
Gomez-Pelaez, A.J., R. Ramos, V. Gomez-Trueba, R. Campo-Hernandez,E. Reyes-Sanchez: "Izaña Global GAW station greenhouse-gas measurement programme. Novelties and developments during October 2011-May 2013" in GAW report (No. 213) of the "17th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases, and Related Measurement Techniques (Beijing, China, June 10-14, 2013)", edited by P. Tans and C. Zellweger, World Meteorological Organization, 77-82, 2014 (Link to the paper).
Sepúlveda, E., Schneider, M., Hase, F., Barthlott, S., Dubravica, D., García, O. E., Gomez-Pelaez, A., González, Y., Guerra, J. C., Gisi, M., Kohlhepp, R., Dohe, S., Blumenstock, T., Strong, K., Weaver, D., Palm, M., Sadeghi, A., Deutscher, N. M., Warneke, T., Notholt, J., Jones, N., Griffith, D. W. T., Smale, D., Brailsford, G. W., Robinson, J., Meinhardt, F., Steinbacher, M., Aalto, T., and Worthy, D.: Tropospheric CH4 signals as observed by NDACC FTIR at globally distributed sites and comparison to GAW surface in situ measurements, Atmos. Meas. Tech., 7, 2337-2360, doi:10.5194/amt-7-2337-2014, 2014 (link to the paper)
Gomez-Pelaez, A. J., Ramos, R., Gomez-Trueba, V., Novelli, P. C., and Campo-Hernandez, R.: A statistical approach to quantify uncertainty in carbon monoxide measurements at the Izaña global GAW station: 2008–2011, Atmos. Meas. Tech., 6, 787-799, doi:10.5194/amt-6-787-2013, 2013 (link to the article)
Sepúlveda, E., M. Schneider, F. Hase, O. E. García, A. Gomez-Pelaez, S. Dohe, T. Blumenstock, and J.C. Guerra, Long-term validation of tropospheric column-averaged CH4 mole fractions obtained by mid-infrared ground-based FTIR spectrometry, Atmos. Meas. Tech., 5, 1425-1441, doi:10.5194/amt-5-1425-2012, 2012 ( link to the article)
Gomez-Pelaez, A.J., R. Ramos, V. Gomez-Trueba, R. Campo-Hernandez, E. Dlugokencky, T. Conway "New improvements in the Izaña (Tenerife, Spain) global GAW station in-situ greenhouse gases measurement program" in GAW report (No. 206) of the "16th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases, and Related Measurement Techniques (GGMT-2011) (Wellington, New Zealand, 25-28 October 2011)", edited by Gordon Brailsford, World Meteorological Organization, 76-81, 2012 (link to the paper)
Chevallier, F., N. M. Deutscher, T. J. Conway, P. Ciais, L. Ciattaglia, S. Dohe, M. Fröhlich, A.J. Gomez-Pelaez, D. Griffith, F. Hase, L. Haszpra, P. Krummel, E. Kyrö, C. Labuschagne, R. Langenfeld, T. Machida, F. Maignan, H. Matsueda, I. Morino, J. Notholt, M. Ramonet, Y. Sawa, M. Schmidt, V. Sherlock, P. Steele, K. Strong, R. Sussmann, P. Wennberg, S. Wofsy, D. Worthy, D. Wunch, M. Zimnoch, Global CO2 fluxes inferred from surface air-sample measurements and from TCCON retrievals of the CO2 total column, Geophysical Research Letters, 38, L24810, doi: 10.1029/2011GL049899, 2011 (link to the article)
Chevallier, F., P. Ciais, T. J. Conway, T. Aalto, B. E. Anderson, P. Bousquet, E. G. Brunke, L. Ciattaglia, Y. Esaki, M. Fröhlich, A. Gomez, A. J. Gomez-Pelaez, L. Haszpra, P. B. Krummel, R. L. Langenfelds, M. Leuenberger, T. Machida, F. Maignan, H. Matsueda, J. A. Morguí, H. Mukai, T. Nakazawa, P. Peylin, M. Ramonet, L. Rivier, Y. Sawa, M. Schmidt, L. P. Steele, S. A. Vay, A. T. Vermeulen, S. Wofsy, D. Worthy, , CO2 surface fluxes at grid point scale estimated from a global 21 year reanalysis of atmospheric measurements, J. Geophys. Res., 115, D21307, doi:10.1029/2010JD013887, 2010.(link to the paper in JGR website).
Gomez-Pelaez, A.J., R. Ramos, E. Cuevas, V. Gomez-Trueba, 25 years of continuous CO2 and CH4 measurements at Izaña Global GAW mountain station: annual cycles and interannual trends; Proceedings of the “Symposium on Atmospheric Chemistry and Physics at Mountain Sites (ACP Symposium 2010, June 8-10, 2010, Interlaken, Switzerland)”, 157-159, 2010 (download pdf)
Levin, I., T. Naegler, B. Kromer, M. Diehl, R. Francey, A. J. Gomez-Pelaez, L. P. Steele, D. Wagenbach, R. Weller, and D.E. Worthy, Observations and modelling of the global distribution and long-term trend of atmospheric 14CO2, Tellus (2010), 62B, 26–46 (download pdf)
Gomez-Pelaez, A.J., Ramos, R., "Improvements in the Carbon Dioxide and Methane Continuous Measurement Programs at Izaña Global GAW Station (Spain) during 2007-2009", in GAW report (No. 194) of the “15th WMO/IAEA Meeting of Experts on Carbon Dioxide, Other Greenhouse Gases, and Related Tracer Measurement Techniques (Jena, Germany; September 7-10, 2009)”, edited by Willi A. Brand, World Meteorological Organization (TD No. 1553), 133-138, 2011 (download pdf)
Gomez-Pelaez, A.J., Ramos, R., "Installation of a new gas chromatograph at Izaña GAW station (Spain) to measure CH4, N2O, and SF6" in GAW Report (No. 186) of the "14th WMO/IAEA meeting of experts on Carbon dioxide, other greenhouse gases, and related tracers measurement techniques (Helsinki, Finland, 10-13 September 2007)", edited by Tuomas Laurila, World Meteorological Organization (TD No. 1487), 55-59, 2009 (download pdf)
Gomez-Pelaez, A.J., "A brief overview of the theory of flow along GC packed columns and some practical consequences for measuring atmospheric CH4, N2O, and SF6" in GAW Report (No. 186) of the "14th WMO/IAEA meeting of experts on carbon dioxide, other greenhouse gases, and related tracers measurement techniques (Helsinki, Finland, 10-13 September 2007)", edited by Tuomas Laurila, World Meteorological Organization (TD No. 1487), 60-64, 2009 (download pdf)
Masarie, K., Tans, P., Andrews, A., Conway, T., Crotwell, A., Worthy, D., Gomez, A.,"NOAA Comparison activities: Are we closer to the required measurement accuracy?" in GAW Report (No. 186) of the "14th WMO/IAEA meeting of experts on Carbon dioxide, other greenhouse gases, and related tracers measurement techniques (Helsinki, Finland, 10-13 September 2007)", edited by Tuomas Laurila, World Meteorological Organization (TD No. 1487), 33-39, 2009
Patra, P. K., M. Takigawa, K. Ishijima, B.-C. Choi, D. Cunnold, E. J. Dlugokencky, P. Fraser, A. J. Gomez-Pelaez, T.-Y. Goo, J.-S. Kim, P. Krummel, R. Langenfelds, F. Meinhardt, H. Mukai, S. O'Doherty, R. G. Prinn, P. Simmonds, P. Steele, Y. Tohjima, K. Tsuboi, K. Uhse, R. Weiss, D. Worthy and T. Nakazawa, Growth rate, seasonal, synoptic, diurnal variations and budget of methane in lower atmosphere, J. Meteorol. Soc. Jpn., 87(4), 635-663, 2009. (Copyright MSJ). Download pdf.
World Meteorological Organization, “Guidelines for the measurement of methane and nitrous oxide and their quality assurance”, GAW Report No. 185 (WMO/TD - No. 1478), 2009. List of contributors and reviewers: Butler, J.H., Dlugokencky, E., Gomez-Pelaez, A.J., Hall, B., Jordan, A., Klausen, J., Leer, E.d., Scheel, H.E., Steinbrecher, R., Tarasova, O.A., Wielgosz, R.
Gomez-Pelaez, A.J., Ramos, R., Perez-delaPuerta, J., "Methane and carbon dioxide continuous measurements at Izana GAW station (Spain)" in GAW Report (No. 168) of the "13th WMO/IAEA Meeting of Experts on Carbon Dioxide Concentration and Related Tracers Measurement Techniques
(Boulder, Colorado, USA, 19-22 September 2005)", edited by J.B. Miller, World Meteorological Organization (TD No. 1359), 180-184, 2006 (download pdf)
Ripodas, P., Ramos, R., Cuevas, E., Calbet, X., "1984-1999 CO2 time series at Izana (Tenerife). Long range transport effects". Report of the "2 Asamblea Hispano Portuguesa de Geodesia y Geofisica", Lagos, Portugal, 2000, page. 467.
Angel J. Gomez-Pelaez (Program Leader)
Ramon Ramos-Lopez (partial time dedication to this program)
Ruben del Campo Hernandez (partial time dedication to this program)
Vanessa Gomez-Trueba (AirLiquide Canarias staff)