WMO Data Policy for the 21st Century

- The meteorological value chain and the roles of WMO and its Members

The ultimate goal of the activities coordinated through WMO is to enable the citizens and economies of all WMO Members to benefit from weather, climate and related environmental services. This is accomplished via the meteorological value chain[1] (see Figure 1), which starts with observations, our basic source of knowledge about the atmosphere and the climate system, and ends with effective decision-making based on the services they enable. The value chain can be schematically described as follows:

  • Weather and climate observations are routinely made all over  the globe.
  • Those observations are exchanged internationally, including with global Numerical Weather Prediction (NWP) Centres.
  • Global NWP output, monitoring and prediction data for weather and climate are generated and shared with all WMO Members (193 States and Territories).
  • Global NWP output is used by National Meteorological and Hydrological Services (NMHSs) and other entities as a basis for weather and climate information.
  • Weather and climate information services are delivered to users, including national and local authorities, businesses, media, academia and the general public.
  • Effective decisions in response to weather and climate information are made by authorities, agents in all economic sectors and individuals.
Weather_and_climate_service_value_chain.jpegFigure 1. The weather and climate services value chain. All links in the chain must operate effectively to yield success.


The first three links in the value chain (shown in red) constitute the meteorological infrastructure, which must be implemented and coordinated globally as explained in the first article in this issue.  The last three links (in blue) are typically implemented nationally, and in some cases with significant regional elements or partly locally in large countries. Government entities typically play significant roles in all links in the chain.

It is a commonly held view that the most important role of a national government is to protect its people. Hence, within WMO’s sphere of activity, the aim of governments and their NMHSs is to maximize the societal benefits of meteorological, hydrological and climatological information, in particular its use to help save lives, protect property and foster economic prosperity

As discussed in the first article, the global nature of weather and climate makes international data exchange an essential prerequisite to any attempt to monitor, understand and predict their manifestations. This has been recognized for over 200 years, and meteorology therefore has a history of international collaboration on exchange of observations and other types of information that goes back to the invention of the telegraph in the first half of the nineteenth century.

The establishment of the International Meteorological Organization (IMO) and later of WMO was grounded on this recognition. The preamble of the WMO Convention reaffirms the point: “the vital importance of the mission of the National Meteorological, Hydrometeorological and Hydrological Services in observing and understanding weather and climate and in providing meteorological, hydrological and related services in support of relevant national needs which should include the following areas: (a) Protection of life and property, (b) Safeguarding the environment, (c) Contributing to sustainable development…”.

The WMO Convention thus acknowledges that for most disasters that result from meteorological and associated hydrological phenomena, impacts can be mitigated by increasing the capability of Members to prepare for and respond to such events, and there is a need for international collaboration in order to do so.

WMO data policy and the current drivers of change

One of the primary roles of WMO is to facilitate and coordinate the international data exchange needed to support service delivery. The role of its data policy is to articulate the principles of this exchange and the practices that support its implementation:  which types of data will be exchanged, by whom and with whom will they be exchanged, for which purposes, and under which conditions?

While the need for international data exchange is clear and nearly universally understood by the WMO Members, it is not necessarily easy to formulate a policy that is both useable by and acceptable to all Members. Within the common aim to provide weather and climate services to their citizens, there is a broad spectrum of different national implementations, with different assignments of responsibilities to the various actors. There is, for instance, no universal, common understanding of the role of public versus private sectors . There is no universal agreement on which services must be provided by government institutions free-of-charge, versus the role of fee-based services, which may be provided either by private entities or by governmental institutions acting as private entities. An effective data policy must provide enough clarity to allow Members to generate products and deliver services to their constituencies. At the same time, it must remain sufficiently broad and non-prescriptive to accommodate these different national policies and national implementations of the meteorological value chain.

Over the years, the WMO data policy has had to evolve to accommodate new requirements, new application areas, new technologies and shifting political and economic realities. The data policy continues to evolve in the twenty-first century, with a major update being put forth for deliberation by the Extraordinary Session of the World Meteorological Congress in October 2021. There are several major drivers behind this new development, and some of the most important will be listed in the following paragraphs.

First, the phenomenal progress and successful application of weather and climate monitoring and prediction outlined in the first article has led to an explosive growth in demand for weather, climate and related Earth system information from all sectors of society. This has led to an increased recognition of the economic value of all types of Earth system data, which in turn has led to an increasingly diverse group of stakeholders active in the generation and use of these data. Furthermore, in spite of our steadily advancing technological capability, it can be argued that our vulnerability to the adverse impacts of weather is increasing in many areas. More people than ever before in history live in high-risk zones such as low-lying, exposed coastal areas and flood plains. Megacities have their own vulnerability to high-impact weather related to the importance of maintaining critical infrastructures operating in all situations and the difficulties related to potential evacuations. Additionally, ongoing climate change is already now modifying the frequency of high-impact weather phenomena. Improved monitoring and prediction capabilities are needed not just to manage the impact of current weather events, but also to help society understand and adapt to the weather we may expect to see in the future.

Second, the ever-increasing demand for Earth system data and the steady advance of technology, spanning observations, telecommunication and data processing, has led to an enormous increase in the volume of available Earth system data. Developments in ground and space-based remote sensing technology and in the processing speed and memory size of the computers used for meteorological modelling necessitate the adoption of new approaches to data distribution and data access. Older solutions, such as the Global Telecommunication System (GTS), can no longer adequately support the data exchange and must be replaced with Internet and cloud technologies. The WMO Information System (WIS) provides required standards for data formats and meta data (see Article 4).

Third, in recent years many countries, especially the developed, have been moving toward making all publicly funded data generally available as “open data”. Data providers, such as NMHSs, are faced with increasing demand for open access to any data they generate. The European Union spear-headed such an approach with its directive “on open data and the re-use of public sector information” (directive 2019/1024), which its member states are obliged to implement in their national laws. The socioeconomic rationale behind this directive is laid out clearly in its preamble (par. 9 and 16): “Documents produced by public sector bodies of the executive, legislature or judiciary constitute a vast, diverse and valuable pool of resources that can benefit society. Providing that information, which includes dynamic data, in a commonly used electronic format allows citizens and legal entities to find new ways to use them and create new, innovative products and services…”

Fourth, there has been a steady expansion of meteorological observing and modelling practices into adjacent application areas such as environmental monitoring, and the quest for extending both the accuracy and the predicted range of various weather, climate and hydrological phenomena. This has made it clear that an integrated Earth system approach is needed. In order to succeed, this approach must encompass observing network design, making and exchanging observations, integrated Earth system modelling and the subsequent exchange of the resulting model data. 

After a thorough analysis of these drivers and their implications, WMO has decided that adopting a single overarching policy statement that lays out the scope of the data exchange required for the twenty-first century clearly and unambiguously would be the best way to respond and to help the world of meteorology to further progress.

Societal context and external developments

As stated earlier,  in recent years a diverse group of stakeholders have been joining the NMHSs as active or potential participants in the data exchange. These include non-NMHS government agencies, non-profit organizations and various entities from the private sector and academia. This diversity is highly desirable and, if managed properly, will help achieve the breadth of data exchange that is needed for the implementation of the Earth system approach just described. In order to harness the value that such a broad and diverse participation will provide, a WMO data policy must be able to accommodate this diversity in its formulation and implementation. 

In acknowledgement of these opportunities, the 18th session of the World Meteorological Congress adopted the Geneva Declaration 2019: Building Community for Weather, Climate and Water Actions, and agreed to convene a High-Level Open Consultative Dialogue on Partnership and Innovation for the Next Generation of Weather and Climate Intelligence.

The new WMO Unified Data Policy has been developed against the backdrop provided by the Geneva Declaration. Representatives from public, private and academic sectors have participated actively in its drafting. The policy aims to provide win-win opportunities by facilitating broad participation in the free and unrestricted exchange of meteorological and related Earth system data. Through specific language on the practice of the policy and its use of precise definitions, it provides clarity for all parties regarding the expectations placed on them and the benefits they can reap. Broad consultation, involving all participants in the data exchange, will remain a key element of the regular reviews of the policy and practice, with the intention to ensure that the policy stays current and responds to the evolving context.

Key strategic initiatives taken around the world, both in the private and government domains, already illustrate some of the trends mentioned above. A common thread is the involvement of multi-player consortia where all parties benefit from substantial investments in collaborative infrastructures.  Some examples of such initiatives, that have either helped inform the development of the new WMO data policy and/or will benefit from its implementation by the WMO Members, are highlighted below.

Copernicus - Via its Copernicus programme, the European Commission (EC) on behalf of its member states is investing in consolidating data integration and modelling platforms to better leverage and maximize the use of existing capabilities and to build on its critical mass of expertise. The Copernicus programme’s mission is to exploit Earth observations and numerical predictions to generate value added information covering all components of the environment for the benefit of policymakers, researchers, commercial and private users as well as the global scientific community. Copernicus covers six main service areas of which one is focused on climate change and its cumulative impacts (see Article 5). The programme is implemented in partnership with European Union member states, the European Space Agency (ESA), and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), the European Centre for Medium-Range Weather Forecasts (ECMWF) and various other EU Agencies as well as Mercator Ocean.

Microsoft Earth - In December 2017, Microsoft announced a US$ 50 million investment in their “AI for Earth program” to develop artificial intelligence technology to better understand and address the environmental issues facing the planet. As they put it: “Fundamentally, AI can accelerate our ability to observe environmental systems and how they are changing at a global scale, convert the data into useful information and apply that information to take concrete steps to better manage our natural resources.”  AI for Earth aims to provide better access to computing and AI tools. It lowers the barriers for entry for smaller organizations that cannot afford the IT infrastructure investment and creates a community of contributors that will advance AI solutions that are innovative and scalable.

In parallel, Microsoft and other cloud providers are connecting government databases to their proprietary cloud infrastructure to increase the data offering that they make available to their clients.

IBM Environmental Intelligence Suite: Geospatial Analytics - The IBM Environmental Intelligence Suite: Geospatial Analytics is a platform specifically designed for massive geospatial-temporal data (maps, satellite, weather, drone, Internet of Things), query and analytics services from a continually updated geospatial-temporal information database that includes satellite weather and climate information. It makes various transformations to make both historical and real-time datasets easier to use, then enables rapid data discovery. Simultaneously, the Geospatial Analytics is a computational platform for running physical and statistical models on the curated datasets. It aims to support the development of applications including AI and other types of data analytics. 

PAIRS relies on producers of information, such as space agencies and other governmental organizations that generate these data as partners in their Geoscope service, to better the offerings they can provide. The business model is such that clients will pay fees to obtain full access to the data holdings within Pairs Geoscope as well as to use computing time on the platform.

WMO Unified Data Policy on the International Exchange of Earth System Data and its expected impact

Compared to the three existing WMO data policy resolutions it is intended to replace, the new WMO Unified Data Policy will provide a more comprehensive, more flexible and more easily implementable approach to data exchange.

The current (September 2021) WMO data policy is laid out in three separate Congress resolutions, each covering a specific domain: Resolution 40 (Cg-XII, weather), Resolution 25 (Cg-XIII, water) and Resolution 60 (Cg-17, climate). In contrast, the WMO Unified Data Policy resolution covers seven disciplines and domains – together encompassing all WMO Earth system data – in a single policy resolution. Additionally, the new policy expands – from addressing only the exchange between NMHSs – to encompass Members as a whole, and thereby  all entities participating in the exchange, including the private sector and academia.

Similar to Resolution 40[2], the new resolution distinguishes between “core data”, for which data exchange is considered mandatory, and “recommended data”, for which the exchange is strongly recommended. However, in contrast to Resolution 40, the new resolution takes a modular approach to the specification of what, exactly, will be included in these two categories. Specific details on what is considered “core data” and “recommended data” are – or in some cases will be – provided in the WMO technical regulations. New developments can thus be accommodated via amendments there, rather than requiring an update of the policy resolution itself. This makes the implementation far easier to maintain and update than is currently the case.

In terms of its expected impact, the proposed data policy update will stimulate and strengthen the international exchange of observations from all parts of the globe. Increasing the number of observations that are shared internationally for use in global and regional NWP models will help significantly improve the quality of the resulting output. This improvement will be felt everywhere on the globe, but it will be especially pronounced in areas where the current observational data coverage is poor, which is the case in many developing countries. In return, the data policy will help provide free and unrestricted access to a much broader range of Earth system model data products for all Members, which will help them improve and broaden the range of the services provided to their constituencies.

Access to additional data, beyond the traditional realm of meteorological observations, will be critical to the continued development and implementation of the coupled modelling systems used in the integrated Earth system approach. Over the coming decades, these systems, spanning time scales from short-range weather prediction to long-term climate prediction and projection, will need to resolve features at higher and higher resolutions and to incorporate detailed land-surface characteristics that capture the level of location-specific detail required by users. The Earth system, as defined by WMO’s activities, is likely to further expand beyond its current scope. We may thus see the arrival of coupled bio-geo-chemical systems in support of primary production, bloom prediction, carbon intake, management of fisheries, etc. The following paragraphs list examples of recent or emerging application areas that are built on various levels of integrated Earth system approaches. These are areas that will benefit from the Unified Data Policy and further influence its future development via regularly recurring reviews.

Marine: State-of-the-art marine navigation safety system: Various countries are working toward getting better navigational information into the hands of mariners. These countries are committed to developing robust operationalization using dynamic ocean model solutions to provide planned E-navigational and hydrographic solutions for mariners and navigators. Such joint national endeavours between meteorological, oceanographic and hydrographic services are aimed at delivering operational solutions through seamless modelling capabilities. This approach will enable safe and efficient operations of commercial shipping and marine transportation sectors by promoting an ecosystem approach to management of human activities.

Security and Emergency: In the area of Nuclear Event Characterization, there is a need to improve real-time data exchange, computational capacity, machine-learning and artificial intelligence related to ensemble analysis of weather data as well as other data types. This will require further improvements in the accuracy of weather prediction and atmospheric transport modelling, and in the characterization of associated uncertainties. Additional work is also needed to further develop and integrate atmospheric chemistry modelling into atmospheric transport modelling. These upgrades will improve global capacity for nuclear event identification, source term reconstruction and predictive modelling of radiological or other man-made release health outcomes.

Climate Change: Bringing science innovations to address health implications of air pollution and climate change. Research has shown that multiple data sources can be incorporated into air quality models to improve their detail and accuracy. The explosion of data capture and analytical methods can expand the range of model inputs. At the same time, deep learning and other methodologies have the potential to improve the understanding of underlying relationships and to improve predictive capacity, both for daily forecasting and for long-term predictions. Expanded modelling capacity will be used to strengthen the science that underpins regulatory decision-making and to track the health benefits from market-based instruments such as carbon pricing. Tools will be developed to support local public health officials to anticipate and address environmental challenges.

Land and Resource Development: Supporting sustainable land and resource development with analysis ready data. Markets depend on sustainable land and resource development. There is a continuing need to monitor and assess dynamic changes on local, regional and global terrestrial landscape. The ecosystem approach to environmental management focuses on maintaining the capacity of a whole system to produce ecological goods and services. This starts with monitoring and management of, for example, water resources, air and water quality and genetic resources, which maintain the global economy, security, health and well-being. A strong foundation of data and computing infrastructure is required to take an ecosystem approach to enabling advances in assessing the status and trends of Earth’s changing landscape. This emerging capability will facilitate cumulative impacts analysis which will provide specific services as well as intelligence for environmental regulations and policy development.

Soil_moisture_map.jpegFigure 2 - Projected changes in summer soil moisture. Changes are presented as mean multi-model change between 1961-1990 and 2021-2050 using 12 Regional Climate Models (RCMs); with red indicating drier and blue indicating wetter conditions. Credit: European Environmental Agency (CC BY 2.5 DK)

Agriculture: Timely information on weather and climate to monitor drought and manage agroclimate risk.  Some countries have implemented drought watch programmes that use a variety of Earth observations and other data to provide timely information and maps on weather and climate parameters that are particularly relevant to their national agricultural sectors. Resource and environmental agriculture require various meteorological and hydrometeorological services depending on the specific crop, its growth phase or the type and current state of the soil. Tillage, irrigation, seed, harvest or efficient application of fertilizers and pesticides with the constraint of ground water protection depend very much on weather. Soil moisture maps are one example of a product created using geophysical data. Such products allow farmers to see where conditions are wetter or drier than normal, enabling resilience in the face of a changing climate.

Health: Earth observation sciences and emerging and re-emerging infectious diseases. Infectious diseases emerge and re-emerge under the influence of key drivers such as the environment, climate, demographics, and socio-economic and human behavioural changes. These are a challenge public health locally and globally. By broadening the exchange of environmental observations and understanding how these drivers affect disease occurrence, officials can predict when, how and where disease will emerge as well as identify the populations at risk and those most vulnerable. Climate change is expected to exacerbate risks from vector-borne disease (VBD) by permitting the spread of animal hosts, pathogens, vectors and VBDs, the establishment of exotic vectors and the diseases they transmit (dengue, Zika, chikungunya, yellow fever) beyond their historical domains. Climate change is also expected to increase the re-emergence (i.e. outbreaks) of VBDs already endemic in countries or sub-continental regions.

The continuous improvements in weather, climate and related Earth System monitoring and prediction services that the world has witnessed over the past 70 years are linked to better science, better technologies and to the real-time exchange of more varied sources of observations. We live in a time of increasingly sophisticated technologies, and the pace of innovation is accelerating. We are flooded with Earth observations. Social media is providing access to contextual information and unprecedented dissemination mechanisms. High-performance computing platforms are allowing us to tackle previously unsolvable problems.

It is only a matter of time before the fusion of weather, water and climate data, big data technologies and business applications go mainstream. This will change the way people and businesses view weather and water data – and experience its force-multiplying effects on improving life and weather sensitive business decisions. These developments are likely to lead many WMO Members to reevaluate their data policies and their partnership strategies at the national level, and they will have a profound impact on the global meteorological enterprise. The new WMO Unified Data Policy is intended to help Members to adapt to these changes and to continue to provide their constituencies with the best possible services in all WMO’s disciplines and domain areas also in the future.


[1] The meteorological value chain covers weather, climate, atmospheric composition and several related disciplines, which depend on global exchange of data.

[2] The term “core data” replaces “essential data” used in Resolution 40, and likewise “recommended data” replaces the Resolution 40 term “additional data”.


Gerhard Adrian, President of WMO
Michel Jean, President, WMO Commission for Observation, Infrastructure and Information Systems (INFCOM) and Associate Emeritus, Meteorological Service of Canada, Environment and Climate Change Canada
Sue Barrell, Chair, INFCOM Study Group on Data Issues and Policies
Lars Peter Riishojgaard, WMO Secretariat

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