Tropospheric Ozone Assessment Report: Database and metrics data of global surface ozone observations

Martin G. Schultz, Sabine Schröder, Olga Lyapina, Owen R. Cooper, Ian Galbally, Irina Petropavlovskikh, Erika Von Schneidemesser, Hiroshi Tanimoto, Yasin Elshorbany, Manish Naja, Rodrigo J. Seguel, Ute Dauert, Paul Eckhardt, Stefan Feigenspan, Markus Fiebig, Anne Gunn Hjellbrekke, You Deog Hong, Peter Christian Kjeld, Hiroshi Koide, Gary LearDavid Tarasick, Mikio Ueno, Markus Wallasch, Darrel Baumgardner, Ming Tung Chuang, Robert Gillett, Meehye Lee, Suzie Molloy, Raeesa Moolla, Tao Wang, Katrina Sharps, Jose A. Adame, Gerard Ancellet, Francesco Apadula, Paulo Artaxo, Maria E. Barlasina, Magdalena Bogucka, Paolo Bonasoni, Limseok Chang, Aurelie Colomb, Emilio Cuevas-Agulló, Manuel Cupeiro, Anna Degorska, Aijun Ding, Marina Fröhlich, Marina Frolova, Harish Gadhavi, Francois Gheusi, Stefan Gilge, Margarita Y. Gonzalez, Valerie Gros, Samera H. Hamad, Detlev Helmig, Diamantino Henriques, Ove Hermansen, Robert Holla, Jacques Hueber, Ulas Im, Daniel A. Jaffe, Ninong Komala, Dagmar Kubistin, Ka Se Lam, Tuomas Laurila, Haeyoung Lee, Ilan Levy, Claudio Mazzoleni, Lynn R. Mazzoleni, Audra McClure-Begley, Maznorizan Mohamad, Marijana Murovec, Monica Navarro-Comas, Florin Nicodim, David Parrish, Katie A. Read, Nick Reid, Ludwig Ries, Pallavi Saxena, James J. Schwab, Yvonne Scorgie, Irina Senik, Peter Simmonds, Vinayak Sinha, Andrey I. Skorokhod, Gerard Spain, Wolfgang Spangl, Ronald Spoor, Stephen R. Springston, Kelvyn Steer, Martin Steinbacher, Eka Suharguniyawan, Paul Torre, Thomas Trickl, Lin Weili, Rolf Weller, Xu Xiaobin, Likun Xue, Ma Zhiqiang

Research output: Contribution to journalArticlepeer-review

172 Citations (Scopus)


In support of the first Tropospheric Ozone Assessment Report (TOAR) a relational database of global surface ozone observations has been developed and populated with hourly measurement data and enhanced metadata. A comprehensive suite of ozone data products including standard statistics, health and vegetation impact metrics, and trend information, are made available through a common data portal and a web interface. These data form the basis of the TOAR analyses focusing on human health, vegetation, and climate relevant ozone issues, which are part of this special feature. Cooperation among many data centers and individual researchers worldwide made it possible to build the world’s largest collection of in-situ hourly surface ozone data covering the period from 1970 to 2015. By combining the data from almost 10,000 measurement sites around the world with global metadata information, new analyses of surface ozone have become possible, such as the first globally consistent characterisations of measurement sites as either urban or rural/remote. Exploitation of these global metadata allows for new insights into the global distribution, and seasonal and long-term changes of tropospheric ozone and they enable TOAR to perform the first, globally consistent analysis of present-day ozone concentrations and recent ozone changes with relevance to health, agriculture, and climate. Considerable effort was made to harmonize and synthesize data formats and metadata information from various networks and individual data submissions. Extensive quality control was applied to identify questionable and erroneous data, including changes in apparent instrument offsets or calibrations. Such data were excluded from TOAR data products. Limitations of a posteriori data quality assurance are discussed. As a result of the work presented here, global coverage of surface ozone data for scientific analysis has been significantly extended. Yet, large gaps remain in the surface observation network both in terms of regions without monitoring, and in terms of regions that have monitoring programs but no public access to the data archive. Therefore future improvements to the database will require not only improved data harmonization, but also expanded data sharing and increased monitoring in data-sparse regions.

Original languageEnglish
Article number58
Publication statusPublished - 2017

Bibliographical note

Funding Information:
This work is part of the Tropospheric Ozone Assessment Report (TOAR) which was supported by the International Global Atmospheric Chemistry (IGAC) project, the National Oceanic and Atmospheric Administration (NOAA), Forschungszentrum Jülich, and the World Meteorological Organisation (WMO). Many institutions and agencies supported the implementation of the measurements, and the processing, quality assurance, and submission of the data contained in the TOAR database.

Funding Information:
Martin Schultz, Sabine Schröder, and Olga Lyapina acknowledge funding through the Helmholtz ATMO program, support from Andreas Wahner and Astrid Kiendler-Scharr, and technical support from Michael Decker. Paulo Artaxo acknowledge funding from FAPESP and CNPq. Samera Hamad would like to thank Mr. Ali Jabir at the Iraqi Ministry of Environment, Baghdad, Iraq for his help in providing the data from the monitoring station at central Baghdad. X. Xu acknowledges funding from the National Natural Science Foundation of China (grant 41330442). Ma Zhiquiang thanks the National Science Foundation of China for funding grant 41475135. Katie Read wishes to acknowledge specific funding from the UK Natural Environmental Research Council (NERC) through the National Centre for Atmospheric Science Atmospheric Measurement Facility (NCAS AMF). Vinayak Sinha acknowledges the IISER Mohali Atmospheric Chemistry Facility and Ministry of Human Resource Development (MHRD), India for funding. Rodrigo Seguel acknowledges support from CONICYT, FONDECYT Program (Project No 11130177). James Schwab received funding from the New York State Energy Research and Development Authority. Andrey Skorokhod acknowledges funding from the Russian Science Foundation (grant no. 14-47-00049) and Department of Earth Sciences RAS (project no. 0150-2015-0053). Manish Naja acknowledge the support received from ISRO-ATCTM project and ARIES, DST for the observations. Lynn Mazzoleni and Claudio Mazzoleni wish to acknowledge funding from the U.S. National Science Foundation (grant #AGS-1110059) and the Atmospheric System Research (ASR) program of the U.S. Department of Energy (grant #DE-SC0006941). Paul Eckhardt, Markus Fiebig, Anne-Gunn Hjellbrekke and Ove Hermansen acknowledge funding from the Norwegian Environment Agency. Stephen Springston acknowledges support from the Atmospheric Radiation Measurement (ARM) Climate Research Facility program of the U.S. Department of Energy. Margarita Yela Gonzalez and Monica Navarro Comas acknowledge funding for Belgrano through grants MARACA (CGL2004-05419-C02-01/ANT), CE-ORACLEO3 (POL2006-00382) and VIOLIN (CGL2010-20353). Tao Wang acknowledges support from the Hong Kong Polytechnic University (G-S023) and The Hong Kong Research Grants Council (PolyU 153042/15E). Ozone measurements from Gadanki, India were supported by ISRO-GBP AT-CTM project and Department of Space, Government of India. Yvonne Scorgie acknowledges the New South Wales Government as the funding source for the NSW Air Quality Monitoring Network, and the Office of Environment and Heritage and managers of the network and curators of the monitoring data set. Observation data from Pic du Midi were supported by the University Paul Sabatier, Toulouse, France, and CNRS. Valerie Gros acknowledges support from IPEV, TAAF, CNRS and CEA for measurements at Amsterdam Island. Ozone observation at Puy de Dôme was mostly supported by CNRS. Ozone observation at Donon was conducted by a French regional air quality agency, ASPA. The measurements at Jungfraujoch are run by Empa in collaboration with the Swiss Federal Office for the Environment. The monitoring data in Japan have been compiled by AEROS (Atmospheric Environmental Regional Observation System), and obtained from the Environmental Database provided by National Institute for Environmental Studies, Japan. Data from Poland were kindly provided by the Chief Inspectorate of Environmental Protection, Department of Monitoring and Information on Environment, Warsaw, Poland. Data from the Canadian Air and Precipitation Monitoring Network was kindly provided by Environment and Climate Change Canada. The Mt. Bachelor Observatory is supported by the National Science Foundation 559 (grant #AGS-1447832) and the National Oceanic and Atmospheric Administration 560 (contract #RA-133R-16-SE-0758). We thank Carolyn Jordan for help accessing the AIRMAP data. We would also like to acknowledge all former colleagues who initiated the long-term monitoring of surface ozone at various sites many years ago but are no longer active in the field, and we apologize if we failed to identify additional contributors or data set PIs.


  • Database
  • Ground-level ozone
  • Monitoring
  • Tropospheric ozone

ASJC Scopus subject areas

  • Oceanography
  • Environmental Engineering
  • Ecology
  • Geotechnical Engineering and Engineering Geology
  • Geology
  • Atmospheric Science


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