GAW Symposium 2021

GAW Symposium group picture 2017


This year's quadrennial GAW Symposium took place online from

 28 June to 2 July 11:00 am – 3:00 pm CEST

It consisted of the following scientific sessions:

  1. Science for services: The importance of atmospheric composition
  2. Filling critical gaps in observations
  3. Atmospheric composition, pandemics and support for a new health agenda
  4. Earth system modelling and data management

On the last day, three panel discussions took place:

  • Young scientists and capacity building in GAW
  • Embracing diversity in GAW
  • Reflections on Symposium and Way forward for GAW

Thank you very much for your contributions to this year's GAW Symposium! It was a pleasure to see you.


More information and material from the Symposium will be shared here soon.


Session descriptions and agenda

Please find the draft agenda here.

Agenda for parallel session "Quality assurance in GAW: common methods and approaches"

Session 1: Science for services: The importance of atmospheric composition

Session description: A key priority of the World Meteorological Organization is the provision of “science for services,” in other words, the timely, ongoing delivery of high-quality scientific information on which to base policy decisions, support businesses and to inform the public. Measurements, analysis products, and forecasts of atmospheric composition are critical to a wide range of clients in addition to standard weather, climate and hydrological information. In recognition of this, the Global Atmosphere Watch Programme has launched three service-focused initiatives to address the needs of these stakeholder communities as they work toward the UN Sustainable Development Goals. The Integrated Global Greenhouse Gas Information System (IG3IS) supports the improvement and use of greenhouse gas emission information so that governments, industry and civil society can better target opportunities for emission reductions and track progress toward meeting emission reduction goals. The Global Air Quality Forecasting and Information System (GAFIS) aims to ensure air quality forecasting and information is available on global to urban scales, to support the mitigation of the negative impacts of air quality on human health and food production and to guide efforts to improve air quality. And the Measurement-Model Fusion for Global Total Atmospheric Deposition (MMF-GTAD) initiative has the goal of providing global estimates of the input of air pollutants to aquatic and terrestrial surfaces – critical information for protecting biodiversity and water quality in the long term. In this session, we invite researchers, service providers, and the user community to present examples of successful or potential ways in which atmospheric composition-based information is providing critical services to society on regional, national and subnational scales (including urban). The success stories that support the three mentioned initiatives, other services supporting extreme air pollution events and services to health community are welcome to the session.

Session 2: Filling critical gaps in observations

Session description: High quality observations of atmospheric composition are essential to understand how composition changes over time in response to human and natural processes. They are used to support international conventions, to estimate human and ecosystem impacts due to air pollution, and to understand climate radiative forcings. Atmospheric composition measurements are also playing increasing roles in numerical weather prediction and a host of weather and environmental services.   There remain important gaps in the atmospheric composition observing systems, with gaps in geographical coverage of many important parameters. WMO maintains a Rolling Review of Requirements that provides an ongoing assessment of user requirements that are compared to current observational capabilities. There are three atmospheric composition application areas (Monitoring, Forecasting, and Urban services; see for details) that span the diverse requirements of researchers and end-users. In this session, we welcome abstracts that address current and looming critical gaps in the observing system as they pertain to these atmospheric composition application areas. Presentations describing technologies that can mitigate these gaps are solicited; in particular those that address the roles of satellites and low-cost sensors. Presentations highlighting advanced or new emerging observational methods and techniques are also of interest. The session will emphasize also the role of quality assurance/quality control (QA/QC) of observational near real time data in the validation of air quality forecasting/re-analysis models and their QA/QC-feedback to the observation networks.

Session 3: Atmospheric composition, pandemics and support for a new health agenda

Session description: This session will focus on the interactions between atmospheric composition and pandemics and the broader impacts on human health. Over the past year the spread of SARS-COV-2 virus (cause of the COVID-19 disease) has stimulate research communities globally to understand these interactions and to highlight lessons for the atmospheric science, weather, climate communities as well as for the health and policy sectors to develop more robust response strategies. Broader messages are emerging to improve and enhance existing infrastructures and forecasting and response capabilities which will be particularly relevant for WMO/GAW.

This session is being held in partnership with WHO, WWRP and WCRP to (i) review the status of knowledge on the interactions between the atmosphere and pandemics, (ii) highlight key gaps and lessons that are relevant for policy on air quality and health and (iii) to make recommendations on the closer cooperation between the atmospheric composition, weather, climate and health communities. With a particular emphasis on forward look, the key themes of this sessions will be:

(i) New knowledge on the interactions between atmospheric composition, weather and climate and the spread of viruses and biological materials;

(ii) New initiatives to enhance atmospheric composition modelling and observations to further our understanding of the impacts of pandemics and the spread of biological materials; and

(iii) Role of atmospheric composition research to better prepare for future pandemics, support the health community and identify areas of infrastructure development.

We welcome abstracts for oral and poster presentations on research that is sufficiently mature to contribute to one or more of the above themes.

Session 4: Earth system modelling and data management  

Session description: The atmosphere is the component of the Earth System that is most directly affected by human activities through changing its composition. This cuts across all spatial and temporal scales and underpins observed changes in inter alia deposition fluxes, air pollution and climate forcing. Session 4 calls for contributions about recent progress in investigating the role of atmospheric composition variability and changes on short, medium and extended range weather forecasting, climate modelling, impact modelling as well as about new insights regarding composition/dynamics/radiation/microphysics feedbacks at process level. In short, the session will showcase and discuss progress regarding the question “why atmospheric composition representation matters?” for modelling & data assimilation of the Earth System as a whole, bringing additional value on top of “composition for composition sake” applications that will be the focus of Session 1. An area of specific interest is the fast emerging use of Artificial Intelligence techniques (observations filtering/selection, data assimilation, model emulation, data mining, downscaling…) and contributions on this aspect are especially welcome. Finally, we invite presentations discussing requirements and gaps related to interoperability of data and metadata, examples of end-to-end solutions building on WIS and WIGOS, progress in automated near-real-time quality assessment and quality control of observations in support of global, regional or local atmospheric composition data services in academic or operational settings.