World Meteorological Organization

The WMO Information system (WIS) is a coordinated global infrastructure responsible for telecommunications and data management functions and is owned and operated by WMO Members. WIS provides an integrated approach suitable for all WMO Programmes to meet the requirements for routine collection and automated dissemination of observed data and products, as well as data discovery, access, and retrieval services for weather, climate, water, and related data produced by centres and Member countries in the framework of any WMO Programme. It is capable of exchanging large data volumes, such as new ground and satellite-based systems, finer resolutions in numerical weather prediction, and hydrological models and their applications. These data and products must be available to National Hydrological and Meteorological Services (NHMS), but also national disaster authorities for more timely alerts where and when needed. WIS is a vital data communications backbone for integrating the diverse real-time and non-real-time high priority data sets, regardless of location.

WIS is composed of three types of centres and a communications network

• National Centres (NCs)
• Data Collection or Production Centres (DCPCs) 
• Global Information System Centres (GISCs) 

National Centres (NC)

As is the case in the current GTS of WMO, WIS requires reliable national centres, referred to as NC.  The NC is responsible for collecting and providing observational data and products intended for global or regional distribution to their responsible GISC or DCPC, and distributing data on a national basis.  The NCs coordinate or authorise the use of the WIS by eligible national users.  According to the national policy, more than one NC can exist in a country. Normally the Permanent Representative (PR) of the country establishes the national policy and practice and coordinates the various users. NCs roles can be summarised as follows:

• Collect observational data from within their country
• Collect, generate and disseminate products for national use
• Authorise their national users to access WIS, as required
• Provide observations and products intended for global dissemination to their responsible GISC (possibly via a DCPC)
• Provide observations and products intended for regional or specialised distribution to the responsible DCPC
• Participate in monitoring the performance of the system

Data Collection or Production Centres (DCPC)

Centres that fulfil within specific WMO Programmes an international responsibility for the generation and provision for international distribution of data, forecast products, processed or value-added information, and/or for providing archiving services, are referred to as Data Collection or Production Centres.  DCPCs can also provide basic WIS functions such as metadata catalogues, Internet portals, and data access management.  Examples of DCPCs are the Regional Specialised Meteorological Centres (RSMC) with activity specialization or geographic specialization, as well as the Regional Climate Centres. DCPC roles can be summarised as follows:

• Collect information intended for dissemination to NCs within its area of responsibility (i.e. regional collections)
• Collect special programme-related data and products;
• Produce regional or specialized data and products;
• Provide information intended for global exchange to their responsible GISC;
• Disseminate information not intended for global exchange;
• Support access to their products via WMO request/reply (”Pull”) mechanisms in an appropriate manner;
• Describe their products according to an agreed WMO standard and provide access to this catalogue of products and provide this information as appropriate to other centres, in particular, a GISC;
• Ensure that they have procedures and arrangements in place to provide swift recovery or backup of their essential services in the event of an outage (due to, for example, fire or a natural disaster);
• Participate in monitoring the performance of the system.

Global Information System Centres (GISC)

The regional and global connectivity of the WIS structure is guaranteed by the existence of a small number of node centres called Global Information System Centres (GISC). GISCs primary role is to collect data and information from WIS contributing centres in their area of responsibility and pass information to centres in their area and send information meant for global distribution to the other GISCs. GISCs also ensure information from other regions is distributed or at least, available to, centres within the GISCs area of responsibility. In this way, information used in the provision of weather, climate and water services, and research is collected and distributed regionally and globally as quickly and efficiently as possible.

GISCs play a core role in the management and maintenance of discovery metadata that underlies the data management and information discovery, access, and retrieval functions of WIS. All GISCs hold a synchronized copy of the Discovery Metadata that identifies all information available and exchanged throughout the WMO community. This includes providing links to discovery metadata in partner or collaborative systems such as GEOSS so that the Discovery, Access, and Retrieval (DAR) services in WIS can be used by WMO communities to discover and access information from WMO and other interoperable systems. The GISCs Discovery, Access, and Retrieval services can also be used to provide national DAR for Members own centres, or used to complement national DAR services by allowing discovery of information from other nations and international organizations data centres. A list of GISCs and their status can be found in the WIS Centres Database. The role of a GISC is defined as:

• Receive observational data and products that are intended for global exchange from NCs and DCPCs within their area of responsibility, reformat as necessary and aggregate into products that cover their responsible area;
• Exchange information intended for global dissemination with other GISCs;
• Disseminate, within its area of responsibility, the entire set of data and products agreed by WMO for routine global exchange (this dissemination can be via any combination of the Internet, satellite, multicasting, etc. as appropriate to meet the needs of Members that require its products);
• Hold the entire set of data and products agreed by WMO for routine global exchange for at least 24 hours and make it available via WMO request/reply (”Pull”) mechanisms;
• Maintain, in accordance with the WMO standards, a catalogue of all data and products for global exchange and provide access to this catalogue to locate the relevant centre;
• Provide around-the-clock connectivity to the public and private networks at a bandwidth that is sufficient to meet its global and regional responsibilities;
• Co-ordinate with the Centres within its area of responsibility a WIS telecommunications infrastructure that can meet the WIS requirements for information exchange within the area and that can exchange agreed WIS time-critical and operational critical information with other areas.
• Ensure that they have procedures and arrangements in place to provide swift recovery or backup of their essential services in the event of an outage (due to, for example, fire or a natural disaster);
• Participate in monitoring the performance of the system, including monitoring the collection and distribution of data and products intended for global exchange.

Communications Network

The “Core Network” connects all of the GISCs and is based on the Global Telecommunication System (GTS) Main Telecommunication Network (MTN). 

GISCs connect by dedicated and public networks to centres within their area of responsibility. This connectivity network is referred to as the GISC's "Area Meteorological Data Communication Network" (AMDCN) and includes using Regional Meteorological Telecommunication Networks (RMTNs) of the GTS and the Internet. This allows GISCs to distribute information to centres in their AMDCN from the global community as well as to collect and distribute information between centres in their AMDCN.