The O3as service provides an invaluable tool to assist scientists in visualising ozone (O3) time series from extensive climate prediction model data and calculating and visualising  dates for the recovery of the O3 layer pre-ozone hole levels (an often used reference year is 1980).  The O3as service produces results in the form of figures in publication quality.

The integration of the service in EOSC has increased its capacity to process large volumes of data (in terms of TBs) and to facilitate the management of the complex workflow to generate key metrics. Climate model data has many fields of physical quantities.

The relevant quantities for the ozone column calculation has to be extracted and processed in order to be visualised efficiently. A pre-processor runs on an HPC system, reducing the large data set to the parameters of interest. With this approach, the reduced data can be read by a REST API for further processing and to produce figures without noticeable delays in a convenient way for scientists. 

Added value via EOSC

The EOSC OIDC EGI Check-in shall be used to access the advanced features of the service, i.e. the plotting of advanced figures and saving the plotted data points for further analysis. Under the hood to access data on the data server LSDF the OIDC-agent is used for mounting using WebDAV-HTTP authentication. In order to perform the data reduction/ skimming in the HPC environment the udocker tool is a vital part for running containers in environments where root access is not available. Finally for the deployment of the service resources, the Infrastructure Manager is used to start a Kubernetes cluster at one of the EOSC cloud providers for the project’s Docker containers. To summarize, O3AS it is integrating the following services listed in the EOSC marketplace:

  • EOSC OIDC providers, e.g. EGI Check-In: to access certain functionalities of the service.
  • Infrastructure Manager: To deploy service components on EOSC cloud resources.
  • EOSC cloud resources: to offer O3AS service for users in a timely manner.Apart from these services we also use the following tools developed in EOSC-related projects:
  • OIDC-Agent: To mount data servers using WebDAV – HTTP authentication.
  • udocker: To run the code for data skimming in the HPC environment.


Exploitation paths


The Ozone assessment service (O3AS) is developed within the European Open Science Cloud (EOSC) Synergy project to assist scientists to visualise ozone data from large climate models. The climate model output is mainly from the Chemistry-Climate Model Initiative (CCMI) project (now: https:// blogs.reading.ac.uk/ccmi/ccmi-1/, in the future: http://blogs.reading.ac.uk/ccmi/ccmi- phase-two/), with monthly model output from 1960 to 2100 of about 100 different model realisations.

The recent 2018 quadrennial global assessment of ozone depletion (https://www.esrl.noaa.gov/csl/assessments/ozone/2018/) consists of six chapters and five appendices with about 25 people actively working on each chapter and a multitude of people working in support of the preparation of the document.



Related documents

The official documentation of O3as can be found in the following link: 

The site contains also a dedicated section on how to use the service. 


Relevant links

Related publications

  • Tobias Kerzenmacher, Valentin Kozlov, Borja Esteban Sanchis, Ugur Cayoglu, Marcus Hardt, Peter Braesicke, O3as: An Ozone Trend Analysis Service Within EOSC-Synergy, Quadrennial Ozone Symposium of the International Ozone Commission, 3 to 9 October 2021, Online meeting (Daejeon, Korea).
  • Tobias Kerzenmacher, Peter Braesicke, Valentin Kozlov, Borja Esteban Sanchis, Ugur Cayoglu, Marcus Hardt, An online service for analysing ozone trends within EOSC-synergy, European Geophysical Union General Assembly, 19 to 30 April 2021, Online meeting (Wien, Austria) https://meetingorganizer.copernicus.org/EGU21/EGU21-8418.html
  • Tobias Kerzenmacher, Valentin Kozlov, Borja Esteban Sanchis, Ugur Cayoglu, Marcus Hardt, Peter Braesicke, O3as: an online ozone trend analysis service within EOSC-synergy, 5th Data Science Symposium 22 Januar 2021, Online meeting (Kiel, Germany)
  • Peter Braesicke, Ugur Cayoglu, Borja Esteban Sanchis, Marcus Hardt, Tobias Kerzenmacher, Valentin Kozlov, Ozone assessment as an EOSC-Synergy thematic service, ISC High Performance (2021), 24 June 2021 to  2 July 2021, Online meeting

Related news

Valentin Kozlov and Tobias Kerzenmacher: O3as: ein Dienst zur Beurteilung des Ozonzustands, Steinbuch Centre for Computing (SCC) News (Ausgabe 1, 2021, ISSN: 1866-4954): https://www.scc.kit.edu/downloads/oko/SCCnews_01_2021_web.pdf